When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I had jumped into another thread about sealing the gas tank and someone (Peejay I think) mentioned it would be a bad idea on the '83 tank because the pickup tubes are brazed right to the tank (not removable as on later years). I'm going to heed his caution and have decided going to POR15 route is probably not in my future...
I did some more testing and tearing apart today. First I pulled the fuel line at the carb and ran it into a container. I let the fuel pump run for about two minutes and I only got about a cup of gas. I was expecting 1.1 liter/min so obviously something going on with the fuel pump/lines/filter... So it's time to drop the tank. I put the back end on jackstands and pulled the drain plug on the tank. This is what I got out of the tank:
Not a great pic, but the take-away should be the amount of fuel in the pan... I only got about a quart out of the tank! The fuel itself looked reasonable (not obviously full of crud), but I only got a quart. Apparently I ran out of gas...
Not being one to let obvious solutions deter me, I decided to go ahead with the tank removal so I can clean and inspect what I've actually got going on inside the tank. After a bit, I got it out:
There's definite surface rust on the outside, but more importantly there is also a reasonable amount of visible rust inside (from what I can see thorough the filler hole). It's not horrible inside there (from what I can see). I've got an inspection camera I plan to drop in there tomorrow to get a more complete picture of interior condition. Already working on tracking down a radiator shop in the area that will be willing to dip the tank for me...
While taking the sending unit out I (of course) broke two of the mounting screws:
I swear that I did not put *that* much force on them, in fact one of them had actually broke free and I was just unscrewing it when it decided to fail on me... Hopefully they're soft enough I can get a sharp drill bit to bite into them. I didn't really try to get them out yet since I want to deal with the lingering gas fumes before introducing the sparky tools...
Anyway - progress is happening. Given the condition of the tank, I am happy with my decision to go ahead and drop it. I'd rather know what I've got then keep wondering if the tank is shedding.
I've got a shop lined up to clean the tank. I asked if they could seal it as well and they said they could - I'll have to talk to them when I drop it off to see how they would deal with the pickup filter that's in the tank.
Here's a shot of the filter inside the tank:
The filter itself looks in surprisingly good shape - but obviously the tank definitely will benefit from a cleaning.
Is that filter in any way serviceable? It looks like if I had 1" diameter arms that were 2ft long I could just reach in there and pop it off - Not having those arms I'm not seeing a viable option...
I suspect any attempts at sealing the interior of the tank would seal up the mesh in that filter pretty good. Which is a shame, because after getting it cleaned I would like to preserve it for as long as possible...
Anyone have any thoughts on getting those two broke sending unit screws out? I've tried all the "usual" methods and not having any luck. I cut a slot in the protruding screw and it just twisted off again. Tried an easy-out style extractor - no luck. I suspect I could easily drill it out and retap to a slightly larger size, but that would require (I suspect) drilling through into the tank. If I did that I'm not certain the flange is welded/brazed to the tank well enough to prevent a leak around the threads getting out? Any thoughts would be appreciated. Thanks!
Tank is at a local radiator shop - they didn't seem to concerned with either the condition or the in-tank fuel strainer when I dropped it off. Did say it's likely to take a couple of weeks before I get it back though...
So I've turned my attention to the fuel sending unit. It wasn't working when I pulled it from the tank, which wasn't too surprising after I saw the condition it was in. Exterior was rusted pretty bad, but more concerning the parts inside the tank were covered in a thick, powdery substance. I didn't think to take any before pics of the crap -- I almost immediately took a stiff brush to it to knock most of it off. After a fairly thorough brush down, this is what it looked like:
It still didn't read right with an ohm meter (read open consistently). I spent a bit of time trying to track down exactly where the continuity issue was and found two distinct problems. First, the spade on bottom in the pic above is no longer making any contact with the metal body of the unit. I assume it's supposed to, otherwise there's no reason for it being there at all... Second issue seemed to be a very inconsistent continuity between the sweeper arm and the metal frame. From what I can see, the sweeper arm is supposed to make contact with the body through the float arm hinge. There was so much corrosion buildup on everything (the brass bushing, the float arm itself, the metal body where the float are and brass bushing touch it) that continuity was very hit and miss (mostly miss).
I ended up having to take the whole thing apart (not messing with the resistive wire wrap) to clean all the mating surfaces:
Once everything was cleaned up and put back together, the sending unit is once again reading correctly...
Except - the large spade on the connector is still not making contact with the metal frame...
I am going to try to solder a wire from the spade to the cover, but it that doesn't go well, I guess it'll be a wire from the spade to a ring connector to go under one of the mounting screws.
I like your approach to this. Before I ran any extra wires, I'd be tempted to remove and refurb the riveted connection between the top spade and the internal connection point. Maybe it's a bit risky but I think going with the original design is a good plan. But if that's not practical, plan B for me would be a gas-safe grommeted wire run through the sender cap rather than the periphery of the sender cap....seems like the latter would interfere with the gasket.
I already soldered the tabs to the plate... I had to break out my old Weller 140 Watt gun, but with that and a bit of extra flux I was able to get the solder to wet both brass tabs and the steel plate. It's not the prettiest solder job, but it's making contact and I'm pretty certain they're not cold joints (even though they look like it):
I pulled the fuel pump and all the check valves in the fuel lines - god what a tangle of hoses that is!
I've already cleaned most of it up and will be giving all the metal a good paint, then back on with new hoses and clamps.
I was really tempted to give FrakenRex's zinc plating process a try, but I think if I started now I would feel compelled to go back and pull at the bits I've already done on the car and redo them... So I've finally convinced myself to hold off on that for whatever my next project turns out to be...
Waiting to hear back from the shop that has the tank... I finished cleaning up all the fuel pump bits. Everything got blasted (except the pump itself), then primed and painted with SVT undercarriage...
When dropping the tank I managed to break one of the mounting tabs off the plastic shield between the fender and the tank (hiding the fill tube). Didn't take any pics of it, but basically the whole corner of the panel broke off. Yesterday I decided to try to fix the shield using a small fiberglass patch kit.
I messed up, in that I was assuming I could get the fiberglass mat to roll over an edge - nope. I'll see how it comes out, but it is just an undercar shield so I can't imagine I'll screw it up too badly...
After doing both sides, letting it setup for a few hours, trimming with the dremel and cleaning up rough edges with the air grinder with a flap roll:
Then a quick spritz of black primer:
Certainly it's far from perfect - but I think it's a reasonable job. Also, it feels stronger than the original plastic - so I think that's a done job...
Picked the tank up from the radiator shop last week. They did a decent job of cleaning out the inside, but no sealing.
I addressed the outside of the tank. Before:
During:
and after:
Fuel pump with new soft lines installed and ready for the tank to be reinstalled.
Tried installing the tank yesterday -- decided it's going to have to wait until I get a buddy to help. Even with a floor jack lifting up the tank it's going to take a couple sets of hands to get the tank positioned and straps installed... Hopefully this weekend.
A buddy came over saturday and we got the tank reinstalled. I finished buttoning it all up (shields, etc) yesterday and put 5 gallons of fresh gas in it.
Then I tried running the fuel pump with the fuel line to the carb pulled - wanted to both flush anything out of the hard lines (which I didn't replace) and verify decent flow to the carb.
I got nothing - the fuel pump refused to pump.
Today I pulled the pump again - everything was bone dry. Bench tested the pump and no bueno.
I disassembled the pump down to the electric motor. That ran when power was applied, so I reassembled the pump carefully checking at each step that the pump still ran.
Got it all back together and tested it pumping gas - it worked well.
Put it back into the car, tested the fuel line at the carb - nice flow - all is looking good.
Put the car back on the ground and tried to start it - wouldn't start.
Checked the fuel line at the carb again - nothing.
It seems this pump is just on the hairy edge of working/not-working...
After searching for an OEM replacement - they seem to be no longer available anywhere I could find.
I read through a bunch of posts describing replacing the pump with one that pumps at a higher pressure, then using a regulator to reduce down to 3.5 PSI.
I decided to give this pump a try: https://smile.amazon.com/gp/product/B01B7DCO6Q
It appears to be a rebrand of the MrGasket 42S I saw mention of in the posts. Max PSI is 3.5, 28 GPM. Looks like it can be made to fit in the original location.
I figured for $20 I'd give it a shot...
One of the most frustrating parts to find is an original fuel pump. I fear we may be looking at doing things similar to what you're doing in the future.
Thanks - just a little time with the flap wheel to get the surface rust off, a quick wipe down with acetone, some primer and a VHT chassis paint...
I think the fuel pump is going to drive me bonkers. After ordering the 42S I linked above, I started reading the reviews and it seems some folks had issues with the brass inserts for the fittings pulling out of the plastic housing. This got me a little worried, so I also ordered another all metal inline pump (about the same price). That one was rated for 4PSI though, but I was hoping that would be low-pressure enough to not overwhelm the carb. The metal pump also came with a connector on the wires that matched the original connector - I figured that was a good sign.
Here are all three pumps together to get a feel for them:
While the mounting tabs for the new pumps are similar to the OEM pump, they are not quite identical. I fabbed up a couple of standoffs to mount the metal pump using the original mounting points on the bracket:
Painted:
And all assembled:
I installed it this morning. Verified good flow at the fuel input line to the carb. Hooked it up and gave it a shot...
Everything seemed like it was working ok - the new pump was slightly louder than the original, but with the rubber isolators nothing bangy or too obnoxious.
Then I popped open the air cleaner and took a look down the throat of the carb. I saw gas pumping down the front barrels. I cut power and pulled the plugs. Front rotor plugs were flooded, rear rotor seemed dry.
So, now I need to pull the pump again and try the plastic one. That one is theoretically 3.5PSI max - hopefully it wont over power the carb...
Well, I swapped out the new metal pump for the new plastic one and now it doesn't flood the carb - so that's good.
Having read reviews that complained about the brass inserts falling out on the plastic pump - I did some pre-emptive tugging on them and the inserts seem firmly seated.
Hopefully that is last time I need to pull that freaking pump bracket off, although I'm pretty sure I could do it my sleep now...
I was in hurry to test out the new pump, so I forgot to snap any pictures of it installed on the bracket...
With it installed I verified that fuel was flowing through the lines and that I didn't see any fuel leaking into the carb. Then I put the plugs back in and gave it a start.
It started right up, but won't idle on it's own. Without a light foot on the accelerator it will just stall (this is just idling out of gear - still up on stands).
The choke doesn't seem to make any difference. I didn't dig into it at all tonight, figured I'd just leave that for when I have more time... Hopefully just needs an idle screw adjustment, but the fact the choke didn't seem to make any difference makes me think it's not going to be quite that easy...
Oh, the new pump (plastic 42S) seems about as quiet as the original - meaning I can hear it running from inside the car (engine off) if I listen for it, but it's not something you would notice if you weren't listening for it.
This week I've been fighting with the car not wanting idle. I started a new thread for that problem here: https://www.rx7club.com/1st-generati...issue-1152653/
so I won't rehash any of that adventure here. But bottom line is that I had a vac line clip interfering with the operating rod on the coasting valve causing the shutter valve to be stuck half open. Once I figured that out and moved the clamp out of the way the car idles fine - yay!
I got that all worked out this morning and this afternoon I gave the car a quick wash to get all the shop dust off it (clean cars always run better don't they?). Then I warmed it up, ran through the idle/mixture adjust procedure one last time and took the car for a test drive. I only drove it a few miles down to a gas station and filled it up, but I got plenty of eyes on it while filling up. On the way back at a light the guy next to me rolls down his window and yells over "what year is your Rx7?" I tell him '83 and he tells me that was the car he always dreamed of having back in the day. Feels good that at least some folks out there can still appreciate the classics
Once out on the road the car ran pretty good. I could definitely tell it felt a bit stiff and tired, but after a little bit it started to 'loosen' up quite a bit. I didn't get the RPM over about 4.5K, but it felt good to get it back on the road at least for a little bit...
I think the next step is to start thinking about the heater core. I know something related to it started leaking (back in the early 90's). I dread ripping out the dash to get to it, but I'm sure there will be lot's of stuff to keep me busy once I start that...
After giving the car a wash I found that the deteriorating driver door seal is apparently bad enough it needs replacing:
One of the things I did while playing with the carb earlier in the week was found that with a few small tweaks the original exhaust manifold heat shield would fit around the RB headers:
So, the car is starting fine, idling fine, seems to be running fine - but I didn't notice this when I first fixed the coasting valve issue: When the choke is on (on a cold start) the car is NOT going into high idle. I didn't notice it, because the car only needs a few seconds of gas pedal to get to the point that it will idle just fine (at about 750). Once in that mode, it doesn't care whether I've got the choke **** pulled or not.
The choke ****/cable IS actuating the choke butterfly valve at the top of the carb, and the linkage down the rear of the carb is moving/pivoting. The other end of that linkage is moving another lever - but I'm unable to visualize the far end of that linkage to see what isn't happening...
When trying to get an eyeball on what is/isn't happening with the choke linkage I did notice the following:
So, I managed to not get the throttle sub-return pivot in the proper place. Fixed that, and not difference - still no high idle.
Any thoughts on what may be going on, or is my best bet to bite-the-bullet and pull the carb off again. I figure if I can miss that pivot, there may be some other linkage I didn't get put 'back together' correctly (I didn't mess with most of that whole linkage assembly when I rebuilt the carb - figured I was better off just leaving everything as it was)...
Well I pulled the carb off today... ran into a little issue - I couldn't get the accelerator cable to disengage from the accelerator arm (part 143 in the carb manual). I couldn't get the cruise control arm to flip out of the way to allow the nub on the accelerator cable to pop out of it's hole... It turns out that somewhere along the way I have managed to totally mangle the throttle return spring lever (part 145):
The throttle sub-return lever may also be tweaked - it's hard to tell with the other lever being so bent out of shape...
I suspect I did this when I put the sub-return lever back in place after I noticed it wasn't engaged yesterday.
So this is a huge bummer -- the carb manual specifically warns against disassembling the throttle arm/lever assembly, but I don't think I'm going to be able to fix the bent levers without at least partially disassembling it...
I can tell cruise control and accelerator arm springs are both being affected by the bent arm on the return lever - I hope they haven't been bent out of shape.
I'm seriously surprised that car even started and ran with this lever so mangled and jamming up the other arms - but it did, assuming this damage was done when I reattached the sub-return lever, after that I started the car and revved it a little and everything seemed just like it did when I went on the test drive a day or two earlier...
Wish me luck, because I'm probably going to start disassembling the arm assembly tomorrow...
Crap - lost my original post...
[EDIT - ok, now the original post is back... sigh... I'm just going to leave this one here too.]
I pulled the carb off the car today. Ran into a problem though, the accelerator cable didn't want to disengage from the accelerator arm:
I couldn't get the cruise control arm to swing out of the way enough to let the nub on the end of the cable to come free.
It turns out that the throttle return spring lever (part 145 in the carb manual) is pretty badly bent out of shape and jamming up the cruise arm:
I did get it to come off and got the carb out of the car, but once on the bench it became clear that the throttle return spring lever (and possibly the throttle sub-return lever (part number 148) is pretty badly mangled:
I suspect this happened yesterday when I pulled the throttle sub-return rod back into position - I'm guessing now that wasn't a good idea...
I'm surprised the car ran at all with these arm so messed up, but it did...
The only way I see of getting to the mangled parts and carefully straightening them back out is to disassemble the throttle arm assembly. The carb manually specifically warns against this, but from where I'm at right now I don't see any other alternatives. So wish me luck - I'll probably dive into it tomorrow...
I partially disassembled the throttle arm assembly, just enough to get down to the throttle return spring lever. Both that lever and the throttle sub-return lever appear to have been bent. Luckily the two coil springs on that arm do not appear to have taken any damage. While doing this I also believe I've determined why I was missing fast idle with the choke - it looks like the hot start assist lever assembly had 'popped over' its spring. The fast idle lever looks like it's supposed to push against the host start lever when choke is engaged and with the hot start lever over extended there wasn't anything to push against. I have to admit though that I don't see how the hot start lever has any affect on the throttle?
Anyway, here are my throttle return and sub-return levers:
I know the first one is definitely bent, I'm 95% confident the second is as well...
I am assuming that both of those bent arms are supposed to be pointing straight up (in the orientation I have them for the pics) - can anyone confirm that for me?
The pics in the carb manual make it appear that this is the case, but confirmation from someone with first hand knowledge would be very helpful.
(I will probably post this as a tech question just to get more eyeballs on the specific question).
Thanks in advance for any suggestions.
Toruki - in that bottom pic the arm on the throttle return lever definitely looks like it goes straight back (towards the body of the carb) which would correspond to "up" in my pics.
I can't quite make out the throttle sub-return lever (hangs off the left end of the rod with the spring over it). I *think* I can make it out in the pic, but not certain. If it is what I think then it also looks like it goes straight back.
Actually it's hard to imagine either of the arms would do anything other than go straight back, but who knows.
Thanks for the pics!
KansasCityREPU - I wish!
I did take tons of pics and even a 360 video of the carb before I touched anything, but somehow I *always* manage to miss getting the angle I really need later on...
Ok, l am now more intimately familiar than I ever expected to be with all of the levers, springs, spacers, etc on the throttle arm assembly.
I am (reasonably) confident that I have the two bent parts back in their original shapes, and all of the other bits-n-pieces properly assembled. It took a bit more noodling and digging that I expected, but in the end that was good because I have a much more complete understanding of all those bits and I'm certain it's back together properly now.
While I had the carb off the car I decided to make 100% certain I had the gasket between the main body and the throttle body installed correctly. Carl mentioned it in my other thread on this issue and even though things seemed like they were ok on my carb, I just had to pull it part to check. Good thing I did! Sure enough, I managed to install that gasket flipped, just like he warned against.
I am more and more surprised that the car ran as well as it did when I test drove it a week or so ago... Anyway, now, I've checked and doubled checked everything, so it's just a matter of getting it back on the engine and seeing how things go...
Time for an update... I took the car for a little test drive on Saturday and it performed admirably
I'm pretty sure that the carb is 100% at this point. Before the test drive I went though all tests on the vacuum actuators to make sure everything was per the FSM.
I do still have an exhaust rattle (damn heat shields!).
And I noticed some kind of clunk coming from the rear when I went over bumps in the road at a little bit of speed - It wasn't obvious where it came from, so I will likely go through the rear end just making sure all the bolts are tight. Hopefully I'll find out the jack is loose...
My driver door seal was toast, so I ordered replacements for both doors and both inner and outer window seals from Mazdatrix and Atkins. They arrived, so I've replaced those as well now.
I have to say that the Mazdatrix door seals (the ones they had made, not OEM) are a perfect fit and match my original OEMs extremely closely - I was quite impressed.
Since I had to pull the door cards to replace the inner window seals (well, I don't know if technically I had to or not, but I did) I've decided to take a look at my slooooooow power windows. I'm sure they would benefit from lube on the main gear, but I think the big improvement is going to come from adding power relays between the switches and the motors. With the door card off I powered the window motor directly from a 12v source and they moved up and down with authority, so I'm pretty sure my main issue is resistance in the OEM switch path for the power. The relays came in today, so those should be going in fairly soon.
Also while I have the door cards off - has anyone successfully managed to refurbish the top vinyl section on the original cards? My cards are in good shape overall, but the top section (vinyl down to the silver piping) is toast:
I could probably live with the discoloration and the wobbly piping, but the top edge is in really bad shape on both:
From what I can tell, it appears the vinyl, piping and fabric are joined by some form of heat sealing, not normal sewing:
The vinyl section at the bottom is definitely sewed to the fabric, but at the top it doesn't appear to be. Here's a shot from the back side of that seam:
Note the lack of any stitching, plus this side was not melted together either (the rule slides right between the two pieces)...
I don't have any experience with interior fabrication, but I'm not opposed to learning. Not quite willing to just tear these apart though, because other than those top sections they're in pretty good condition...
I had an 83 with the burgundy interior and the door vinyl was eaten by the sun, just like your example. I fixed it by cutting off the old vinyl and sewing on new "naugahyde" in a matching color. I don't recall if I kept the silver trim or not. In your case, I think you could. Leave at least an inch of the discolored vinyl, get some new stuff and sew from behind right along the top edge of of the chrome. I wish I had a picture of mine from back in the 80s.
06-21-21, 06:49 PM
