The regular MS V3.0 board needs an uprated circuit for the BAC valve. Not sure what the MS V3.57 board has for the idle circuit but it it's the same may have fried the transistor in that circuit. I think from memory the MS3X board has a uprated circuit that can be used if you are wired into the mainboard idle circuit.

 

I'm actuay using the idle output on the expander board, which doesn't require any external circuitry. I have added a flyback diode as well, just in case.

 

yes, you might use the same one as the Fuel Pressure Regulator does. the stock one is neat though, at full throttle it should show some positive pressure

 

Interesting. I might try the bottom nipple on the front of the dynamic chamber for the FPR, then use the stock FPR nipple for the MAP sensor. It looks like it would give the best average of all the runners.

 

I checked my datalogs and found that there is a discrepancy between the internal temperature gauge reading and the reading from the ECU. While the internal gauge showed peaks of 97C (207F), the ECU logged a maximum of 198F (92C). Given that my internal temperature gauge is a $40 eBay part that's about 5 years old, I'm more trusting of the ECU sensor. I'm also running Shaniac's timing map (with timing pulled at idle to keep it smooth), and everything feels good so I'm just going to leave it for now.

Yesterday night (forgive some of the flash photography) I worked on the full-range TPS conversion. I'm using the same Mustang TPS as most of these conversions use, but I wanted to make my own bracket rather than purchasing one. I first thought about replicating some of the brackets I see online and locating the TPS on the front of the throttle body, like stock:



But it's a bit crowded here. Now the commercially available brackets seem to use a small adapter that fits on the end of the shaft, and then locate the sensor further out to clear the OMP linkage. However, I have a large Taurus alternator there. So I asked myself, why locate it there when I have more space here?



The back of the throttle body has lots of space, since the dashpot and thermowax are eliminated due to the standalone. The TPS is designed to be rotated only in the one direction, so we need a small adapter piece:





It drops into the side of the TPS that normally fits over the shaft:



Then allows the "back" side of the TPS to accept the throttle shaft:



Looking at the mounting options on this spare throttle body, it's actually pretty easy. The center of the dashpot mount is directly in-line with the throttle shaft, so we just need a flat rectangular piece of steel with some minor bends:



Cutting and bending the steel at midnight (we have plenty of space between us and the neighbours, so hopefully the angle grinder didn't wake them):



Then notched it to fit the sensor, drilled the mounting holes, and painted it:



There we go. Full-range TPS without deleting any factory functions (that wouldn't be already deleted with the standalone). And it doesn't interfere with the Taurus alternator.

I have yet to actually install it though, since I currently have the accel-pump function working quite well and don't want to mess with it yet. So for now I'll put it aside until I have a few hours to mess with the settings.

Until next time

 

I've been working on some small things lately, none of which lend themselves well to pictures. Neatened up the tune a bit, but it's working well enough that I can get in the car and not think about it. Adjusted the hood latch so it no longer tries to pop open while driving (only when going over a really big bump, but still, a major safety hazard). Chased down a few interior rattles. There are two improvements I've made which are worth documenting though.

First, I finished the full-range TPS conversion. When we left off, I had finished the bracket and adapter for the throttle linkage. The next step was to extend the wiring, since I've installed the TPS on the other side of the throttle body:





Conveniently I already had the necessary 3-pin Yazaki connector:



A piece of split-loom tubing to protect the wiring:



And then some tape to hold it all together:



I had a good think before deciding how to wrap it. I didn't bother wrapping the new Megasquirt ground or CAS cable, since both of them will be integrated into the new harness once I swap in the 13BT. This sensor deserves more attention since I will only be changing the connector to match the new harness, and possibly shortening the wiring depending on the routing. The split loom is because this wiring runs over the intake runners and fuel rail, so it provides some abrasion protection. The tape on the outside of the split-loom is TESA engine harness tape. Electrical tape is not ideal as it becomes sticky with heat. Silicone self-fusing tape would probably be better than the TESA tape to prevent fluid ingress, but being frank, I just hate the way it shines. I re-wrapped most of the body harness in the engine bay with the silicone stuff and it bothers me every time I see it. Then I used the fuzzy interior harness tape on the ends, as I find that it sticks better and doesn't come unravelled at the ends like the TESA engine harness tape. When I make the new engine harness I am going to investigate that nice woven mesh sheath that I see people using.

After spending far too much time pondering wiring harness tapes, installation took less than five minutes:



If you're wondering why I didn't mount the TPS upside down to make the wiring neater, it's because there's a hump in the side of the TPS facing away from the camera. When flipped this hump interferes with the bracket and causes the TPS to sit sideways on the throttle shaft. Notching the bracket would remove one mounting ear, so it would necessitate a new bracket with a different design. And frankly, this one is good enough for now. I have a container full of little harness p-clips, but I've misplaced it. For now I'll let the wiring float. There isn't enough length for it to flap around much.

I left the old TPS connected for now. As you can see the harness-side connector has been through a lot in it's life:



I have the new connector, but I'm going to leave well-enough alone for the time being. This whole area is going to receive some much needed TLC with the new harness.

One other thing I chased down was some rattling from the rear speakers. In particular, whenever there was a heavy bass kick. I pulled off the speaker covers and tested, but still heard some vibration. Then I pulled out the speaker itself and found the culprit:



Damn. I don't know whether to be happy it was that easy, or upset that I've been hearing that rattle on and off for months and continually putting off fixing it.



I decided to add a bit of foam to the speaker covers as a precaution. This isn't to provide a seal, just to prevent rattling. Conveniently the little track that Mazda left along the outside of the speaker opening is the perfect place to put some foam. The foam presses against the mounting flange of the speaker when installed.

In this picture you can also see some cracks forming in the corner I repaired on the defective spoiler. I got a few years out of the repair and it was my first time using fiberglass, so I'll still call it a success. It's something I'm going to fix when the car is already experiencing downtime.

And lastly, this isn't something I have actually installed yet, but it's too neat not to share it:



These are the sunroof deflector bracket pieces I modelled a few weeks ago. Need-a-t2 was kind enough to machine me a beautiful set out of aluminum. It's pretty cool, I designed this part myself and now I'm holding it in metal. It's neat to see your own part become a reality. Thanks again need-a-t2! I'm going to inspect my current ABS parts when I remove them, and then after verifying they held up I'll make a small write-up and share the STL file.

Until next time

 

My pleasure. Thank you for openly contributing to this community. It's getting harder to keep these cars on the road, and the more people contribute, the better off we all are.

 

That's awesome. Nice team up to crank out a couple of needed parts!

 

With some free time this morning, I decided to investigate something that's been bugging me a bit. The steering in my car is working quite well, it just has one odd quirk: It only re-centers itself about 95% of the way. This requires manual correction on my part, and while it isn't really a safety issue, it should be addressed. I find the more you need to think about how you're driving the car, the less you enjoy the act of driving it.

So I put the car on stands:



My research brought up the usual suspects; steering rack, inner tie rods, outer tie rods. All of these are rebuilt or new. So I checked them anyways, finding no issues. I played with the yoke adjustment on the steering rack as well, no difference. Then my research told me that the wheel bearing being loose can do this.

I've found the best procedure to check a wheel bearing (or really any other suspension component) is to just jack up the car and try to tear the wheel off with your hands. If you make any progress at all, there's a problem. In my case I found some up and down play on the passenger side. Now luckily I have less than 5000km on these wheel bearings, so it just needed tightening and not a full replacement:



I used the factory torque spec of 14-22 ft-lbs, erring on the higher side. The wheel spun smoothly but the slack went away. I checked the driver's side and gave it the same torque spec. But then I noticed on the driver's side there was no up and down play, but some side-to-side play. I found a different culprit:



None of the crusty looking components, everything is new, it's mostly mud from the end of my driveway. And not the ball-joint itself either. The mounting nuts. Both mounting nuts were loose. I removed them by hand. And I can say with 100% certainty that these were tight before I got my alignment, because I specifically went and re-torqued all the suspension components to spec beforehand. I don't normally go blaming the shop for a small mistake, but that's pretty serious. I removed the nuts and cleaned the area before adding anti-seize and torquing them down... or torquing them up, whatever the correct term is. Then I bled the brakes in the front, because why not:



Now, I spent some time second guessing whether I had left the ball-joint nuts loose or the shop had done it. The rear of the car was already lifted though since I wanted to check on a transmission fluid leak, so I checked the rear suspension too. Guess what else was loose?



Yup, the upper lock-nut on the camber link. Now it was only loose on the upper nut, so it couldn't back out all the way or anything, but still. Come on. I also pay more than market rate for my alignments since I trust that my usual shop does good work, and they have in the past. I've seen them install my lug nuts properly with a torque wrench rather than banging them on with a rattle-gun, which is what made me comfortable taking it to them. So I'm willing to accept this is a one time error, but I'll still be keeping one eye open for another shop. Alignments are the only thing I outsource since I don't have the equipment to do it as accurately as a shop, and still it's wrong.

The transmission fluid leak turned out to be coming from the plate on the side of the shifter housing, which makes it a transmission-out job. The transmission will already be coming out when I swap the TII driveline. So I'm just going to keep throwing cardboard under the car for now. And if you've noticed some of the rust on the suspension in these photos, so have I. I stripped and repainted everything a few years ago and they were looking great until last fall. Shows you what one winter does to a car. Nothing serious, and nothing on the body of the car, but still.

After fixing the issues the steering wheel still doesn't return to center perfectly, but it's definitely better overall. It feels much sharper and has less tendency to tramline on poor roads. It's a small but noticeable difference. I think the steering wheel could be over-tightened too, since I can remove the nut but can't pull the wheel off the column. I don't know if an over-tightened wheel could cause this issue, but it's the only thing I haven't tried, and since there were issues with the rest of the alignment I no longer trust that it was torqued to spec and not rammed on there. I used to be able to pull the wheel from the column by hand, albeit with a lot of force. Further investigation will be required.

Overall, improvements have been made. Until next time

 

Good thing you caught the ball joint fasteners, that could have ended poorly. You've got me second guessing myself, I might have to go through my rear suspension and make sure I torqued everything down I was supposed to.

 

It's funny, I was thinking that I had become too paranoid about that sort of thing. Not that it shouldn't be checked, but checking every fastener before a shop visit was beginning to feel excessive. Now it turns out I need to check every fastener before AND after a shop visit.

Speaking of which, I tried again to remove my steering wheel. I pulled it hard enough I was afraid to break something in the steering column, tried a rubber mallet, etc. It absolutely won't budge. When I first removed the nut on the column after my alignment, I had to use an electric impact wrench to loosen it. So I may need to get a steering wheel puller.

 

try just rocking it back and forth. also keep the nut on by a couple threads, when it does decide to pop off it won't attack

 

That's what I've been trying, but it still hasn't budged. I've just spent 15 minutes pulling at it, rocking it, using a rubber mallet, etc.

The original wheel was on the car for 32 years before I bought it, and it wasn't this hard to remove.

Going to keep at it for a bit, but I don't think this is going to work without a puller.

 

I spent a good half hour last night trying to remove the steering wheel, with no success. I used a two-jaw puller to try and pull the wheel off, but the wheel started to bend instead of pulling from the column. Not just flex, but actually bend. So I stopped and decided to leave it alone until I have a three-jaw puller. This morning though, that became unimportant:





Yup, grease and ATF pouring from the driver's side steering rack boot. At a certain point, it's starting to feel personal!

Having become very practiced at removing the steering rack, I find the best way to drain the fluid is to loosen the clamps on the return hose and remove it from the pump side, and cap the pump inlet. Then direct the hose into a container and spin the pump with an electric ratchet:



Makes quick work of the draining process. Then flip the hose to the pump side and let anything else drain. That will get the bulk of the fluid out.

Anyways, a rebuilt rack with a 3 year warranty is on order. I was hoping to buy more parts for the turbo swap, but at this point I am not going to bother rebuilding this rack again. I'm certain I got it right last time and it still failed, so maybe the minor scratches on the rack itself are too much and it is no longer a good core. And the rebuilt rack was only a bit more expensive than having my rack rebuilt professionally (which again, wouldn't help if the core is bad). The rack won't arrive until at least next week, but this is exam week anyways so my time is limited.

It's a bit disappointing, but overall I'm not that upset. I may try de-powering the old rack properly, since it is no longer suitable as a powered rack. Plus I'm an expert at rebuilding it due to the multiple efforts. One thing is for sure, I'm going to ask the next shop I take it to for alignment not to over-torque the column nut.

Until next time

 

The rebuilt steering rack arrived today. Out of the box it seems okay-ish:



There are exactly three things that concern me:

- First, the line at the back that runs from the pinion housing to the far side has a slightly unusual bend. I'm guessing it was dinged on removal from the previous car, and then no-one at the rebuilder noticed.

- Second, the rack came with a little notice that "there will be no returns accepted for a rack with damaged threads, and all threads are inspected thoroughly before the rack leaves the factory". Which wouldn't be a problem, except the threads on the return line port were clearly a bit funky out of the box.

- Third, they did the lazy rebuilder thing and just spray painted the whole assembly silver (painting right over grease while they did so) instead of blasting it or painting the parts separately. This is purely cosmetic, but still.

Taking the old rack out was fairly straightforward, since I've done it so many times. Undertray, battery, tray, e-fan, and sway bar come out. Then it's a few fasteners and you're ready to pull the rack:



I tried counting the threads for each tie-rod end, but the inner tie-rods had a different amount of thread. So instead I measured the width of the old rack from the outer edge of one tie-rod stud to the other. Then without moving the tie-rod ball joint, I installed them on the new rack and adjusted to maintain length. Then I installed it in the car, with my dad helping to hold the steering wheel straight (since I can't remove the wheel to recenter it):



If you look closely, you can see the problem I mentioned with the hardline. Out of the box, the line collided with both the mount bracket and the bolt. I adjusted it a tiny bit by hand and it now clears, so it should be alright:



It's a bit frustrating that a rebuilt part comes out-of-the-box with this lack of attention to detail. Especially since they offer a limited warranty but then immediately wash their hands of it with 15 disclaimers in the box. It wasn't cheap either.

Having everything installed, I added fluid and carefully bled the system. Then I checked for leaks and took the car for a drive.

Overall, it's hard to say if the rebuilt rack has fixed anything (other than the leaks, of course). The steering now returns to center even less than before. Part of the issue is probably that the steering wheel is no longer centered. This means the angle sensor for the computer is also not centered, so that probably contributes to the issue. Even though it tracks straight I am still going to get an alignment (leaving the new shop a note politely asking not to over-torque the steering column nut) to eliminate all possibilities. I don't actually expect the alignment to make as much of a difference as the loosening of the steering wheel...

Today was my last exam, and after it was complete I visited some family in Toronto. I also picked up something really cool. A member of the GRM forum contacted me, and generously offered me a Turbo II driver's seat that he had reupholstered and mounted as an office chair. When I asked what he wanted for it, he told me it was free to a good home!



The dark spot in the photo is from the nap on the fabric; if you brush all the fabric the same direction it looks consistent. He reupholstered it himself in this nice dark fabric, and it even has an embroidered logo:



Really impressive work.

He also surprised me with some cool Rx-7 related reading material; Road and Track - On Mazda Rx-7, November 1985 Car and Driver, and Sports Car Colour History - Mazda Rx-7. Really neat stuff.



While I am tempted to mount the seat in the car (I slide all around my leather GXL seats when turning), the leg is falling off my current desk chair. So for now at least it will remain an office chair. Thanks again Curtis!

Hopefully I can get an alignment sometime next week, work schedule permitting. Until next time

 

I mentioned before that the puller started to bend my steering wheel. So I had to dig in a bit deeper before proceeding. First I removed the column plastics, which both came free with a loud pop:



I could feel a bit of friction between the hub and the plastics, but didn't realize just how much the hub had ground out. Keep in mind that I actually cut this fresh OEM piece for the hub when I first got it and there was zero collision, so this is purely from the nut being over-tightened. Here's some of the ABS dust I found floating around inside:



And as if that wasn't sign enough, the nut was tightened so hard that the bottom of the nut started to mushroom out. Also, the split lock washer used to be a lot more "split"; it's been flattened out some:



And I pulled a nice pile of shavings from the threads:





Then I had the hub exposed, which let me use the puller to grab the outside circumference:




(The little cup on the puller is bent, but it still sits fine on the flat of the column. It was adjusted after this photo was taken).

And since the hub was much sturdier than the wheel, I could actually pull it free. Not without a lot of effort though. I cranked it all the way down by hand, then with a breaker bar, and then I used a Ryobi electric impact wrench on the highest setting. After about 30 seconds of impact, it made a very loud "bang" noise and moved about 1/8". Then I tried to remove it, but it was still stuck on there. So I impacted it again for 15-20 seconds, and it made another loud bang, and moved another 1/8". And I just kept at it until eventually it came free.

It was on there so far that it was hitting the plastic assembly that holds the steering angle sensor. Which is way too far. If that isn't clear enough to visualize, here's another way to look at it:



That round mark is from the spring-loaded plunger for the horn contact. It gets a dollop of grease, and spring pressure holds it against this slipring and makes contact for the horn. The scratching isn't unusual since there is metal-metal contact, but what is unusual is that the entire ring was creased inward along that line. Not in the extreme, but enough to be visible. This means that it was on there so far that the spring compressed entirely and the horn contact was slowly rolling a bead into this brass ring. Wild.

With that apart, I replaced the horn wire (broken on removing the hub), then put it back together. And man, what a difference.

I don't have a great frame of reference since my Celica feels entirely different, but the steering now feels more natural. It returns almost all the way on it's own (not 100% though), but I'm having a hard time telling what is normal anymore. I have changed so much on this car in the past few years that I only vaguely remember how the steering felt when I got it. I took a test drive and stopped to take a few photos:





The speed-sensing function of the computer is quite nice. You can feel it vary the assist as you accelerate, and then the angle-sensing function lets you make small inputs easily and then gives firm road feel for larger inputs. Really neat. Plus, since the wheel is straightened out and the car isn't wandering at speed (due to measuring the old rack before installation), the alignment is no longer urgent.

So for now at least, I'm calling the steering fixed. I might still get that alignment just to eliminate every possibility regarding the wheel centering, but the required correction is very minimal so I'm not too worried.

Until next time

 

One thing I had hoped to avoid when I bolted up wider wheels was modifying the body. With stock style springs in the front though, you are limited to around 8" due to the size of the coil, and you need to get the perfect offset to achieve that. Now since I am running 7.5" wheels with a 225 tire I thought I could get away with it:



The potholes at the end of my driveway had other ideas though. Every time I leave the driveway I get some rub on the tire, and it pulls down this little spot on the fender. So it was time to do some rolling. I bought Amazon's finest fender rolling tool:



It's exactly like all the reviews say; If you're okay with the fact that it's manufactured to the nearest 1/4" and don't mind having to loctite every fastener on it before use, it's perfectly fine for the price. If I intended to use it more often I would have sprung for the Eastwood version, but this one is fine for my purposes. And yes, I did realize the little rings on the handle are for the conical lug nuts before I actually started rolling.

I used the heat gun to get everything softened up, but since my paint already has some chips and cracks in this area, I was really just looking to minimize any further damage. Normally you would start with the tool inside the wheel well and angled to push the lip up, but I started by just pushing the lip of the well back into it's original shape. Then I angled the tool and slowly starting working the lip up and folding it over:



It took about 15 minutes start to end on the driver's side. Then I moved to the passenger side. The hardest part was that the nut on the end of the tilt adjustment for the tool would back out when I turned the handle to push the roller against the lip. So I would have to turn the handle, then spend a couple minutes tightening the nut with a wrench to actually push the roller where I wanted it to go. A bit of a pain, but again, that's what I get for buying the cheap tool. After working away at it for awhile:









No paint damage, which is nice considering how old my paint is. I didn't take it to the extreme. I just wanted to roll the lip up enough to prevent any more rubbing, not actually change how it looks. The new profile should be enough for now, but I'll be checking periodically to make sure I went far enough.

I also fixed the rolling tool with some grease in some areas and loctite in others. It now works very well, only to sit on my shelf indefinitely. Until next time

 

I thought I was done for the day earlier, but I squeezed in one more improvement on my Rx7. I mentioned before that I was sometimes seeing the coolant temps become higher than expected while cruising. At this point they certainly aren't too high at about 194F when cruising on a fairly hot day, but it's higher than I think it should be.

One idea I had for the cause was that the fan shroud is too restrictive. I'm currently using a Ford Taurus electric fan. It's a perfect fit for the rad and it cools the car very quickly when active. However, the shroud itself might be a restriction at higher speed when air is trying to squeeze through the radiator. Namely, this big flat area:



Others who have installed this fan cut out the top and bottom sections for radiator hose clearance. When I installed it, I decided to swap the corners (they are inversely shaped) and use some JB weld and scrap ABS to glue them in. This helps the fan remain effective when operational since it has to suck air through the rad, and not just circulate air in the engine bay through those openings. There is an opening at the bottom of the shroud which I left untouched, specifically because I was concerned about airflow at speed.

What I traded off in fan efficiency, I compromised in all-out cooling. I'm no airflow expert, but even a layman like me knows that the flow through the core is bottlenecked by the opening for the fan, since it can't escape through any other avenue. So I thought, maybe I should add a way for it to bypass air at speed but not do so at idle. It turns out radiator flaps are already a thing, but I'll be making my own since the only one I found available commercially was more expensive. Especially considering the commercial kit was just a flat piece of rubber and some rivets.

So I bought some flat pieces of rubber and some rivets. First step was to take a rough measurement:



Make the cut. Precision isn't important, but there's about 1/4" flat on the bottom and sides and 1/2" on top. This way the rubber will rest against the flat brim, and the 1/2" is to give me space for rivets:



Added some rivets with those little rivet-washers (I don't remember the proper term):



Then I installed it back into the car:



Then this is how it should work. When at idle or low speed and the fan activates, the suction inside of the fan shroud should hold the rubber flap shut, like this:



Then when at higher speeds and the fan is inactive, air pressure in the shroud from the air flowing through the rad should hold the flap open. Like this:



This gives the air a place to go when at speed, and should help cooling.

I took a test drive and found that under relatively similar conditions I was getting a 7 degree drop, cruising at around 187 degrees. MAT was cooler on my second drive though, so some of that temperature drop is probably unrelated. It's safe to say that it's dropped at least a few degrees, but I can't pin down exactly how much.

Long term, the best thing to do is to get serious about ducting. I'd like to get some more LRB pieces like the radiator panel and undertray. Since they're flat, it's easier to add foam to them than to the stock pieces. I have some sheet aluminum that I could use for the purpose, but the LRB parts are so nice I'd rather just save up and go with those. I could also make a smaller shroud with a generic round fan and try that out, but the Taurus fan works so well at idle and low speed that I'd like to retain it if possible.

For now at least, the car is still running within acceptable temperatures.

Until next time

 

I mentioned earlier that I had a transmission leak from the shifter housing, and had determined it was an “out of the car” job. I had intended to just keep parking on top of a piece of cardboard until the Turbo driveline swap, but then plans changed and a vacation got cancelled. This left me with free time to take care of the leak and a few other small things, so why not?

Forward section of the exhaust needs to come out:



Catalyst:



Shifter, starter, and driveshaft came out, and then the slave cylinder can be unbolted and tied out of the way. Next is the heat shield that goes between the exhaust and the transmission:



You can see the gear oil soaking the shield. One thing to note is the long linear deposit; this tells me the output shaft seal is probably leaking as well. Luckily I have a new one ready.

After that the transmission is ready to come out. Five fasteners at the engine, four on the crossmember, and then it just pulls free. I have yet to find a proper way to remove the transmission because it tends to hit the rear of the shifter opening and want to hang up. Jacks are clumsy since upward pressure to hold the transmission up fights you trying to pull the transmission back out of the engine.

My improper way is to just lay on my back, put my feet on the bellhousing, grab the tailhousing, and pull it down and out. Then just carefully lower the transmission down onto my body (emphasis on “carefully”) and roll it over and out of the way. The NA transmission is light so I can do this trivially, but the Turbo II transmission is quite a bit heavier. So when I do the swap I’m going to have my dad help me and use some jacks, no matter how clumsy they are.

With the transmission out and pivoted to the side, we can see the shifter housing:



Yup, greasy. I took out the spring-loaded parts that make the shifter return from the 5-R area to center. Laid out like an exploded diagram:



The plate, spring, and plunger with the steps in it are the parts that resist pushing the shifter from center to right. Then when you let go they spring back. The little spring and ball-bearing on the bottom hold inside the step on the plunger.

I noticed some blue RTV was used on the plate for the spring and plunger:



I thought it may have been myself that did that way back when, but then I saw this on the other side under the inspection plate:



Yeah, no way that was me. I can see myself using the RTV, but I cannot see myself using RTV and not cleaning all that crud out from the housing. Looks like the dissolved remnants of the original shift bushings, plus some dirt?

First I went to clean the small parts. My dad picked up a new toy that’s really neat; an ultrasonic cleaner:



These things are cool. You toss in some parts, add liquid (degreaser, mineral spirits, kerosene, etc) and press start. It heats up the liquid bath and blasts the parts with sound waves to help loosen the dirt. I left that for a bit while I cleaned the shifter housing:



I cleaned the gasket surfaces with a razor blade and then used brake cleaner and scrubbed awhile. This was all the detritus that came off:



I also cleaned the speedometer cable seal by hand. I had to be careful not to lose it; according to my Mazda dealership I purchased the last one in existence.



To be continued.

 

Continued:



I finished cleaning the shifter housing, and came back to check out the fruits of the ultrasonic cleaner:



No, not the world’s worst soup. The parts:



Squeaky clean. All I did was drop them in and then pull them back out. Even the RTV came off easily with a bit of elbow grease, which was a pleasant surprise. Everything went back into the housing in reverse order of removal, using RTV as I didn’t have new gaskets for these parts. I also popped in the new output shaft seal.

With the transmission out, it was an opportune time to repair some stripped threads on the shifter mounting hole. I have been babying it awhile with careful application of blue loctite, but it was time to repair it correctly. I’ve never used a helicoil, but these things are pretty neat.

Drill out the threads:



Tap with the special tap in the kit:



Attach helicoil to tool:



Then you just thread it in, and punch off the little tang on the end. I added some red loctite to the outside of the helicoil just to be sure.

Changing gears for a moment (ha!), I started to work on the exhaust. Awhile back I made a nice aluminum heat shield to replace the stock piece that had disintegrated years ago. I installed it on a spare manifold to verify fit, and that’s where the project halted. Unfortunately the manifold on the car had all the bolts for the heat shield broken off, and there was little access to remove them. So I just lived with it.

Having the transmission and exhaust already disassembled gave me an opportune time to swap in my spare manifold with the heat shield on it already.

I knew a mouse had made a nest in the spare manifold, but he wasn’t hurting anyone so I decided to ignore it for the time being. I was careful not to move the manifold from its place on the shelf so I didn’t disturb him. But today was the day to evict him, so I grabbed the manifold off the shelf and started removing the nest.

I assumed he wasn’t in there since I didn’t see him flee, but then I reached in and grabbed something crusty:



He died like he lived; Inside my exhaust manifold.

Here’s a better view of the heat-shield:



It’s just two pieces of aluminum cut to size, two rivnuts, and a couple rivets on top. Overall it should perform decently. Installed:



Then I put the transmission into the car and reassembled everything. Last was to fill up the shifter housing with fresh fluid:



Then I popped the shifter in and it’s good-to-go.

And it works. No pictures, since the car looks 100% identical to before. All I did was stop the transmission fluid leaks, and as an added bonus the orange exhaust RTV I used on the catalyst flange helped eliminate an exhaust leak. How long will it last? Probably not that long. In the meantime I’m just going to be happy with it and not worry.

The last thing I did was to add some foam to the radiator. I’m assuming that from the factory there was foam here already, but like many other parts, someone probably threw it away at some point saying “You don’t need that.” Just like people do with the undertray, the duct panels in front of the rad, emissions components, the thermowax, the idle valve…

I’ve mentioned before that I want to purchase the LRB undertray (and some of their other fine parts) and then use my spare sheet aluminum to make some proper ducts. I still want to, but in the meantime I just got some closed-cell door lining foam from the hardware store. I layered it a few times and then adhered it to the bottom of the rad:



Hard to see, but it’s there. A test drive showed no difference. Then I used some more to fill the void on the passenger side through which the body harness passes; no difference. Then lastly I filled the driver’s side void where the oil lines run…

Boom. Consistent 5 degrees F drop while cruising under similar conditions to before. As if that wasn’t enough, a 15 degrees F drop during an extended WOT run. I am currently averaging around 179-181 cruising, and peaked at 184 under extended load. I guess the last 10% of the foam really makes 100% of the difference.

I also found that the intake manifold is much cooler, probably due to the exhaust heat-shield and the decreased coolant temps. Granted I didn’t soak it in traffic for long, but after a 20 minute drive I could rest my hand on the plenum, which I have never been able to do before.
Hopefully we get a few more really hot days so I can test it under the worst conditions possible, but so far I’m very happy. Until next time

 

When I first installed the Megasquirt (and a bit later on) I mentioned some issues with sync loss. I was able to mitigate the issues by adjusting the VR pots and re-gapping the pickups, but every so often I would get a couple of lost syncs on the datalog with no apparent reason. Then the other day I noticed that sometimes at high RPM it would lose sync and then have trouble re-establishing it for a few seconds at a time.

Here's the stock CAS:





The wheel I was losing sync on is the upper "cam" wheel. I wasn't able to determine the reason, and despite some fiddling with the pickup gap I wasn't able to completely eliminate the issue. I ordered a small 36-1 wheel and hall sensor with the idea that I could mount them in the CAS itself and avoid modifying the front pulleys, but then when I was asking about it in the Megasquirt section Nosferatu had some really helpful advice. Apparently you can just modify the CAS into a 24-2 wheel and avoid using the upper wheel entirely.

So that's exactly what I did. I found several posts about it, but most were relating to the MS1 and didn't have very clear instructions. It turned out to be pretty straightforward though.

Remove the roll-pin and drive gear:





Take out the pickups, and the screws that hold the rotating assembly:



Pop out the shaft:



Removing the two-tooth wheel is optional, but this ball-joint puller made it a 2 minute job, so why not:



Then grind out two opposing teeth. I read first that it "didn't matter" which teeth you grind out as long as they are opposing. This is technically true, but the best way is to count back from the two-tooth wheel three teeth. There are instructions on this particular step if you search. The only consequence of my choosing the teeth at random is that I had to grind out the adjustment channel on the CAS body a bit to time the engine. Since I've already gone and modified this CAS, I'm not worried about it.

Time to put the CAS back together with its new 24-2 wheel:



I did accidentally kiss the next tooth over with the carbide burr, but it hasn't caused any issues in operation since it's a minor mark. Be careful though, if too much damage is done the tooth won't read anymore.

I technically don't need the extra pickup anymore, but couldn't think of a better place to store it than in the CAS. If I need a spare, I'll know exactly where to find it. I also added a dab of red paint to the third tooth back, since that's how the engine is timed now:



Then I put the engine at TDC, lined up the gears, and installed the CAS. Altering my sensor settings in Tunerstudio took a few tries, but I got it working and timed. After a test drive and re-gapping the pickup to .011", perfect sync. No loss during cranking, no loss at high rpm, no loss when the fan turns on.

So I'm very happy with the modified CAS. What I'm not happy with however, is my own carelessness:



After work on Saturday I went to fill up the tank, and I scraped the curb entering the parking lot. I could go on about how the curb there is unusually tall and it protrudes out a weird angle, but at the end of the day this is my fault. It's fixable, but it still sucks to know that I did that. I can pick up a can of colour match paint from a local shop I know and bang this back into shape using the inner sill for access. I also have a few PDR tools that may help pull that crease back out. I'm going to get it as close as I possibly can, then paint it and call it good. Then add it to the growing list of things that a body shop will need to look at when I get the car painted. Including that bubble on the door.

On the drive home from the gas station, I felt a weird drag on the car. Then I heard a thumping noise and smelled Jiffy Pop. That is my cue to know that a brake caliper has seized. Randomly, for no apparent reason, the caliper on the OTHER side of the car decided to seize up. I pulled over and it was immediately apparent due to the heat radiating off the wheel.

On Sunday I drove my Celica to work and back. Wouldn't you believe it, I pull into the driveway and hear a thumping noise and smell Jiffy Pop again. You guessed it, BOTH my cars have seized brake calipers in less than 24 hours.

Rear calipers for the Rx7 are tough to find, so luckily I kept that free set I got from the parts yard. I tossed one on and bled it in less than an hour, but it turns out that one is even more seized then my original. So rebuild kits are on order for all the offending calipers.

Both cars are back in their natural habitat:



So for now, that's that. I start classes on Wednesday and between work and school I'm looking at 55 hour weeks. I'm going to do the required maintenance so I can continue to enjoy my Rx7, but any major jobs (like the Turbo swap) will be waiting, most likely until spring since I don't have garage access during the winter. The rebuild kits should arrive in a few days and then hopefully I'm good to go.

Until next time

 

When I left off, both my cars had a brake caliper seize randomly less than 24 hours apart. On the Celica it turned out a dust boot was not seated properly from the last time I rebuilt the calipers, so just polishing the piston and removing a bit of rust from the end of the bore fixed it. No rebuild kit required, since the rubber was less than a year old and in perfect condition. I made sure to get that dust boot seated properly this time.

The Rx7 needed a bit more care. I ordered a set of rebuild kits, and started by pulling the calipers:



The first thing I noticed is that my rear rotors are on the wrong side. Doesn't hurt anything, but it looks a bit unusual now that I see it.

The second thing I noticed:



The little post that tensions the return spring for the parking brake mechanism is gone. And so is the spring. I never noticed any weirdness and the parking brake wasn't dragging, so maybe that part isn't really necessary? Either way, the rebuilt calipers will have the spring.

I am actually rebuilding the set I got from the yard for free, since they almost certainly have fewer miles than my current calipers (or any of the rusty parts in my garbage bag full of rear caliper cores). Here's where we started:



The boots were intact when I started, but the piston was quite firmly seized in there. So to avoid further damage I let PB Blaster do some of the work for me:



I let that sit for a day or two, and by the time I came back I was able to remove the pistons (with considerable effort). Here's what we have:



No pitting, but certainly not ideal. New ones are available on eBay, but at $150 per piston that isn't an option unless these are 100% unusable. And they're only about 60% unusable, so I decided to polish them up. Results to come later.

Next I removed this little circlip and plate that sit at the bottom of the bore:





They're related to the parking brake mechanism, which I am not disassembling in it's entirety. I wanted to rebuild that as well if possible, but unfortunately there is a needle bearing inside that is not available as a separate part from the caliper. I am sure that I could find a compatible part somehow, but both shafts rotate smoothly so I am going to leave well-enough alone.

Then all the small parts (and a few big ones) took a dip in the ultrasonic bath:



I then spent a few hours with a variety of picks and brushes cleaning the calipers. I ran a tap through all the threads (being very careful not to damage the seats on the bleed screws), scrubbed all the little corners, etc. I spent a particularly long time with a dental pick scraping every bit of rust from the piston seal groove and dust boot groove. So much time in fact that I forgot to take pictures of it.

However, a few cans of brake cleaner later, you can see the difference between the uncleaned and cleaned caliper:





Some places have a bit of surface rust, but I'm not too worried about that. My main concern was removing all the grease and brake dust before painting. The rust only needed to be scrubbed until it was no longer loose. The best thing for cleaning these would be a hot-tank, but with the parking brake parts still installed that isn't an option.

Once all the parts had been scrubbed, it was time to mask them:



To be continued

 

Continued:

My go-to choice for spray paint is VHT Caliper Enamel (and not just for calipers, but for anything). If you clean the surface really well and follow the directions, it's very durable. The first step was cleaning and masking, which is already done. Then I painted the calipers and brackets:



Then I left them to dry around 24 hours before the final step, which is baking. During those 24 hours I had plenty of time to polish those pistons up:



I'm quite happy with them. It took around an hour for the pair, but I was using Meguiar's Scratch-X because I didn't want to be too aggressive. I didn't want to remove any material, so I decided it was best to play it safe.

And it worked very well. You can still see some swirls in the finish, but they are silky smooth. Then I cleaned them thoroughly and put them with the other small parts.



To bake the calipers, I used a little toaster oven I keep around the garage for this exact purpose. I'm not sure what happens if you bake enamel paint in your kitchen oven, but I'm not eager to find out. I put the brackets in first and baked at 200F for one hour according to the instructions on the label:



I ended up leaving them in there around 2 hours to be safe. Meanwhile leaving the calipers themselves on top of the oven got them nice and toasty, ensuring the paint was 100% dry before baking them at full temp.

I only baked the calipers for the specified hour, because there is a rubber bushing on the end of the arm for the parking brake. I'm sure the bushing is heat-resistant since it's on a caliper, but I didn't want to push it. The heat from braking will cure the paint the rest of the way.

After the parts cooled, I put in the new rubber parts:



I used brake fluid to lubricate all the seals and the inner part of the caliper, then rolled the piston seal in. Then I started screwing the piston in with this handy tool:



Make sure to orient the piston correctly, or the pad won't seat:



They went in very smoothly, which was nice since it was such a fight to remove them. Then I lubricated the slide pin bushing with synthetic brake grease and installed it:



Then I lubricated the slide pins themselves, and reassembled the caliper:



And there we go, rebuilt calipers. Well, mostly rebuilt. I would still like to get those parking brake bearings, but it works fine so as long as it doesn't leak I'm not going to worry. I reinstalled them on the car (after swapping the rotors from one side to the other):



And after bleeding the four corners about 7 times with fresh DOT-4, the brakes feel great.

After a few test drives, I took my car for the longest drive I have done since I parked the car five years ago to start restoring it. I drove it to class (around 40 minutes from me) and back. The highway was a bit terrifying, but it gave me a good opportunity to use the auto-tune to dial in the VE table a bit further. I also definitely need to replace the rear diff bushings (the ones I haven't already replaced, I mean) and the rear sub-frame bushings are due for replacement as well. They aren't completely terrible, but they certainly don't help the highway experience. More on the to-do list for the Turbo swap.

I tried to take a picture of my car in the college parking lot, but my phone defaulted to it's useless "night mode", so this is what I got:



What's the point of "night mode" if there's so much noise it's impossible to see anything? Oh well. Either way, driving it was a lot of fun and there was no drama. I'm calling it a success.

Until next time

 

I use compressed air where the brake line connects to remove the piston, just make sure you drop a piece of wood in where the disc would run, you don't want it flying out. It comes out quite quick and with force, don't get your finger in there.

 

That was something I tried, but I got no movement from either piston. They were really in there.

I don't know any history on the car they came from, but it must have been sitting a very long time.