Repuguy

Hey the car runs again! Yay! I followed advise here, and basically did this

The hardest part was finding the damn fuse holder! I had to run down to a car audio place to get anything even remotely capable of fitting and working. I can find 100 amp fuses all day, but no holders at NAPA, ect. I'll post some pics later.

As soon as I can find one, the FC fuse block is going in to replace the FB links too.

Still can't figure where the hell that gasoline leaked out from, maybe the filler neck? I had JUST filled it, when the car died on me in a parking lot, and then leaked over the intervening hour or so.

Ah and lastly, the motor seems VERY sensitive to timing, i.e. if I move the dizzy 1/8th inch or so left or right, it won't start. Too much advance or retard. I wonder if the bearings are sloppy?

GSLSEforme

Manipulate wires at dist. connections for signal generator while running,possible like other hard/no starting problems you have a questionable connection. Engine not that sensitive to timing 1/8" either way=no start. Pull the cap,rotor,shield,put rotor back on and check for movement in shaft. Take rotor off,hook up remote starter switch and crank engine while watching dist shaft for runout. Look closely at dist cap terminals for any sign of rotor contact. Make sure bearing plate is tight,air gap for pulse generators is correct(.032 is good) and same. Possible this is carb related?

JSmall

Pretty sure car audio cable is a bad thing for battery/alternator wiring aye. Can't remember exact details though. All the correct info on how to wire it all up is on the following link. Series 5 alternators use the same plug connection as an FD unit.

Alternator upgrades -

chuyler1

iTrader: (1)

It all comes down to actual gauge of the wire and how much flexibility you desire. Higher strand count is more expensive to manufacture but is also more flexible and less prone to failure after repeated flexing. The thing to watch out for with audio cable is whether it is safe to use in greasy engine bays and whether the gauge of the wire is properly reported. Most OEM cars only run something like 4ga for the starter and 8ga to the fuse box. You may need 0ga and 4ga respectively from an audio-brand manufacturer to get the same actual thickness. The audio brands elude you into thinking they are spec with their thicker sheath (more common with budge brands than the bigger names in the industry).

Repuguy

Pretty sure you're right on there Chuyler1, it's about strand count, and grease/heat resistance. It's not super high count, but modestly flexible. I don't think it's actually audio cable in my case, they just label it that way.

I finally got he dizzy hold down bolt to hold the dizzy, just needed a new lock washer...

I messed around with all the wiring in the ignition system, that's easy to access, and had no real affect on the rpm/start ability. But I did richen my idle mixture just a hair and now the car starts and idles MUCH easier! After 30 seconds or so it will idle on its own now at around 1100. Im really impressed, I think I'll richen my jets in the idle circuit, and then lean the screws to something more reasonable. I'm at 5280, but I hear other members are using 100 idle fuel jets. The 7 is almost drive able like a normal car!

The headlights are dead now, but I"m 90% sure it's the switch on the column, it's pretty floppy, so a cleaning and then if that fails replacement.

I found out the leaking fuel was from simple overfilling/leaky filler neck. It stopped after leaking 1/4 gallon or so, and if I take a corner sharply, with the tank full, I smell raw fuel. Easy enough to prevent I think.

For those like me who have the smaller M8 or so temp sender with the washer this is the NAPA part you need:
it's only around $18, which is half what Mazdatrix wants. As a side note mine's still not working! I even replaced the bullet connector to the sender, as the old one rotted off. Next step is to check the gauge?

Interestingly my ebrake basically won't hold the car. I know the adjuster is inside the brake handle. I had it tightened to where it would hold the car in my driveway (pretty steep) but it was heating up the disks! I only went around 1/2 mile that way, so no damage I think. But I'd assume there's a proper procedure to tightening this assembly? Lift rear end, spin, apply parking brake, tighten as necessary?

OK last thing I swear, I hear a clunk from the rear, and generally the car feels very 'rattly', I'd like to go through he suspension/bushings. Would you guys recommend Energy Suspension bushings, and stock shocks (Mine seem hardly worn really) or something else?

Repuguy

Got the 7 down to emissions today, finally! I spent a few minutes showing them how to get the hood open, indicate that the Smog pump is there (they had no idea what it was), and pointing out the charcoal can and Smog pump filters. Still failed.

We measure Grams per mile so it's not directly relateable to PPM, but my numbers are like this
Measure Limit
HC 13.9 3.5
CO 114.5 45
CO2 434.8 NA
NOx .249 5



So Like my wideband said, I'm running rich. Very cold combustion low Nox, right? I've messed around with the idle, and now I'm sitting at a fluctuating 14.2/15 AFR at idle, but as I speed up, around 2500 rpm, it drops to 12:1 or so. I think a larger air corrector and possibly smaller main fuel will fix this?

Oh and I'm going to go ahead and connect the actual O2 feed to the cat. I have it just dummied in place. So the cat will be getting restricted, but full time O2 from the pump. I can confirm the pump actually pumps, so that's a plus.

Edit:
Attached a picture of the report. Now that I notice it, I'm much closer to passing, later in the test. I assume this was because the cat was finally warmed up. Those A-holes, let the car sit too long and the cat cooled!

Repuguy

I finally broke down that 13b I've had sitting around. Turns out it's pristine in one side, the apex seals were just carboned into the rotor, and that's why it was making no compression. There's 0 flaking or scratches in the housing, I'm amazed. The Irons look to be in as good or better shape than the ones in my 12a. Unfortunately the front rotor lost part of an apex seal and it damaged the housing, but not the front iron. Not sure what I'm going to do with it, but I'm glad to finally have solved the mystery.

Today I drilled a new hole in the cat, and used high temp epoxy (2k+F) to seal the pipe to the cat. I was going to weld it, but I can't weld stainless, so this will have to do until I can get the car to a shop, bleh.


Went ahead and added 190 airs to my 135 fuels, and the car now is in the mid 13's in the mid-range, better than the 12's earlier. Idle is now between 14 and 15, which oddly fluctuates. But the mid-range (2500+) doesn't fluctuate?

Qingdao

iTrader: (3)

You can weld stainless with regular wire. It will stick just fine only the end result won't be stainless anymore. I have a stainless canister on the back of my car and welded the hangers (which are mild steel) on it... its still hanging in there. (pun level expert)

Repuguy

Got the exhaust all goobered up, but it doesn't leak! I pre-heated the cat with a propane torch and that helped the adhesion. Next step will be converting the welder to DCEN, and some big caps...

(Read this paragraph in Ren's voice from Ren and Stimpy ) I made it to emissions place again today, and I've never dealt with such idiots. First they couldn't start the car. Then they put it on the dyno and 'exceed the speed limits' whatever that means. They try again, and stall the damn car... "I'm afraid it doesn't have any power". They obviously tried to pull a hill in 4th at 1500...Idiots! Have you never driven a Honda or other small car? I take the car home, easily chirping the tires leaving...

OK after that debacle, I realized the IDA downdraft is a bad idea for a street car. Call it a lesson learned. I put the Nikki back on. Needles stuck, and the carb flooded. Burnished the needles with a brass Dremel brush. Floats now work great. Fuel is at/below the middle of glass. Car starts, but only seems to run on the AP shot. Will pull the carb apart again, and check for obstruction in the main jets. Car seems much smoother/quieter with the Nikki than the IDA, I rather like that.

As a side note, the Carter Fuel Pump is much quieter with the return system the Nikki has vs the deadhead on the IDA. I was going to run a return style but couldn't find one in the 1-6 psi range I wanted.

Repuguy

I got the Nikki back on, and when I changed the floats, carefully measured with a micrometer, they were WAY off. Now the fuel's sitting in about the middle of the sight glass, and it's no longer pouring out of everywhere! Car still won't run though. I can start it, but it dies quickly. Basically I have to keep pumping the accelerator to feed it fuel from the accelerator pump circuit.

I pulled the carb off, and removed every single jet/bleed valve/venturi and blew carb cleaner through them. Everything looks clean now, and I'll try it again tomorrow. I did not notice any clear obstructions when I was doing all this, but I may have missed something. If it isn't an obstruction, I cannot imagine why the engine would not be pulling enough vacuum at 2k+ to feed itself. Will double check for vacuum leaks too. Already swapped a new manifold to block gasket and good carb base gasket when I put the carb on, but something could have gone wrong?

Jeff20B

iTrader: (13)

Carb base gasket? The ones from the rebuild kits are not good to use. They don't work like you would expect. They might be the cause of a vacuum leak.

Repuguy

Hmm it is a base gasket from a kit, and I suppose that could be a leak source? I'm not even sure that's what the problem is though. I can't keep it running for more than 20-30 seconds, the whole time pumping the pedal to feed it fuel. I checked the bowls immediately after it dies, with the pump shut off, and neither bowl was dry, nor were they overfull.I had suspected that the Solenoid vent was loosing 12v switched, and was shutting the fuel supply off, but that's obviously not the case either. I did find though that I've likely got a clog in the evap lines, as when I hooked the evap-charcoal canister up, the bowls overflowed.

I'm going to go check the base of the carb, closely, to see if it fuel is leaking out, maybe that would indicate the vacuum leak? Also double checking EVERYTHING is plugged, as I don't trust much to be leak tight atm.

Found out I can keep it running longer, by modulating the choke carefully. I kept it running long enough, that I heated up my O2 sensor, and it confirmed what I was hearing, it was rich, leaning, and then running out of fuel.
I disconnected the return line, and can clearly hear air moving through it with the compressor, into the tank. I did the dame with the feed line. All seems good. I pulled the feed line off the pressure regulator, and ran the pump, I get 26 Oz (.77 liters) in about 10 seconds, so plenty of fuel.

I'm wondering if the needles are sticking in the closed position when running, then with the car off, falling, and allowing fuel to be pushed in again?
If I glance into the bowls, I see fuel though. I'm at loss now. I tried another experiement with some compressed air.

Repuguy

OK, OK, learned something new, maybe helpful. I got the car started, and had a helper open the Secondaries. The car then proceeds to run fine, with only the secondaries. Little shaky, but it works. So I go to open the primaries, and I see a good amount of fuel vaporize in the venturies and feed the engine, just like it's supposed to at ~4k rpm. It died due to fooling around, but likely would have run fine that way.

This got me to thinking, I don't see any gap between the venturi walls and the throttle blades. I assume there's supposed to be some gap, on both primary and secondary barrels? I'm reading through the FSM right now but not locating that exact spec.

Qingdao

iTrader: (3)

The secondaries should be shut until they are in use. There is a set screw for the secondaries. Set it so that so the valve is closed, but not tough to get it open. The primaries definitely need a crack of opening to keep the enginet running.

There is a transition circuit that dribbles fuel down the secondary holes that opens when the primaries are almost wot.


Check this thing out....

http://www.mazdabg.com/ftp-uploads/M...g%20Manual.pdf

That link really helped me out a few years ago when I was messing with my Nikki.

woodmv

iTrader: (8)

^^ THAT is awesome! Thanks for sharing Qindao, I know I can benefit from that manual...

Repuguy

So I figured it out! I went back to basics, and remembering what Jeff20b was saying about vacuum leaks, I found out that my intake wasn't sealing to the block! I took the manifold off, and sanded it flat, on a table-saw bench, which is machined flat. New copper spray and back onto the car and it starts up! Idles kinda rough, around 1100 rpm.

But now it's not easy to start, and floods easily. I have the idle screw out 3 turns, and a tiny crack in the secondaries at rest, or it won't start at all. As a side note, my primaries aren't ported on this motor at all. I am also running the stock jets and air bleeds. It shows around 11.7-12.3 on my afm, so I know something's up. I also hear some whistling sound? That may be the damn air pump, but it's erratic and reminds me of a vacuum leak.

Repuguy

Having found the BIG Vacuum leak, I'm still not sure what's up with this car. I adjusted the secondaries so that they're shut at idle, and it smoothed out, nicely. I'm idling around 1k, and can't seem to lean it out (mid 12's now), or idle it any slower. I should be able to idle pretty lean, and around 750 rpm, yeah? I assume this is a symptom of a vacuum leak? If I transition throttle off idle slowly it will die. It's like one of the transition circuits isn't doing its job correctly. Again, other than the enlarged bores, this carb has stock jets and emulsion tubes and bleeds. I can confirm fuel flowing from all 4 venturies of the throttle plates are opened, which is promising I think.

As an aside, the carb requires Full Choke and Full Throttle to start, and is a little tricky to keep running for the first 30 seconds or so.

Repuguy

Messed around with the 7 again today. I removed the crappy gasket that came with the carb kit that goes between the carb base and the manifold, made some improvement. I can now get a steady idle at 1k and around 13.5-14.3 afr at idle. Probably as good as a ported Rotary is going to do eh?

BUT, there's always a but...if I do anything off of idle under load the car dies. I barely was able to get it 10 feet up the driveway. My afr gauge goes into the red, and it dies. I have all stock air bleeds, and the secondaries are shut tight against the bores. Any possibility that I may have the air bleeds switched around and that would cause this?

Hmm, just realized this thread is kinda pointless (I may be totally off base on what's stock, and according to the carbmanual I am...) without pics! So here's some pics. Primaries, then Secondaries.

Jeff20B

iTrader: (13)

They are in the right places but the problem is in the stock small primary air bleeds which feed the idle circuit and influence the transition circuit and main primary circuit. They are massively too big from the factory. They only work ok on a totally stock Nikki with a choke flap and the rest of the car being stock. Your car obviously isn't stock. You need smaller air bleeds here. I like 118 to 124 because I have the drill bits for them. Your stockers are 180 which is too much air and making your afr go into the red (lean).

You can get a set of 120 air bleeds from eBay for a Mikuni carb which work well in our carbs. https://www.ebay.com/itm/171160615161

Maybe grab a set of 125 as well. Just know the factory tunes air bleeds every 10 numbers, and I've seen Nikkis with 150 (common for SAs), 160, 170 (common for FBs), 180 and 190.

Your carb probably has some other issues that have yet to be addressed, but I can tell you just dropping these idle air bleeds down to around 120 solved so many drivability problems I consider it a must-do mod if you are stepping away from 100% stock.

Repuguy

"They are massively too big from the factory. They only work ok on a totally stock Nikki with a choke flap and the rest of the car being stock. Your car obviously isn't stock. You need smaller air bleeds here. I like 118 to 124 because I have the drill bits for them. Your stockers are 180 which is too much air and making your afr go into the red (lean)."

Absolutely agree. I came to the same conclusion, after re-readign for the umpteenth time your Modded carb threads.

I went through and did a few other things today, because I thought I was chasing a vacuum leak or carb leak.

First I made a brand new carb base to body gasket:


It's made from Fel-Pro 3157, which is a rubberized fiber materiel that's designed to resist gasoline. Whole roll was about $8 from my local NAPA.

Then I sanded smooth the phenolic spacer that sits between the carb and my manifold. It had a ton of crap on it from who knows how many gaskets and goop over the years.
Before:

After:


Then I took gaskets from the carb rebuild kit, and put holes where they're supposed to be and trimmed them a bit, and I have now 2 new gaskets above and below the phenolic spacer.

OK that was fun, but Jeff20b is likely right lmao. But it's nice to do something like that so as to prevent future problems.

Off to ebay for some jets!

Jeff20B

iTrader: (13)

Your phenolic spacer looks fine and doesn't require aftermarket gaskets from the kit. What you sanded flat is the factory bonded permanent gasket and should be all you need (unless you over-sanded it).

Repuguy

Jets showed up in the mail last night. Replaced the stock 180 bleeds with the 120's. Now the car won't run. It sounds like it will catch, but it just wont start. I tried richening the mixture, with the idle screw, from the stock 3 turns, and it got closer but no fire. Also made up some brand new plug wires for the leading plugs, to eliminate the old wires as a source of failure. I'm tired of this...150 HP never should be this hard to get.

Only other thought atm, is vacuum leak, will double check the carb/manifold area.

Repuguy

Aha! Progress! Jeff20b was right on about the 120 air jets, thanks man! I took all 4 plugs out, and cleaned the crap out of them, and the car now runs. Starts almost instantly, no choke required. So awesome. Then if I open the throttle it dies. Ah, upon closer inspection:

What the blin happened here?!


My throttle linkage is all messed up! I wonder if some one was trying to steal the car? Carb come back off time and fix linkage time.

Repuguy

Throttle linkage repaired, carb reinstalled.
Ok, so I've got the car to happily idle below 2k. It sounds mellow and pretty good, not like with the Weber. But I'm still running lean if I crack the throttle and it dies. I can see this on my O2 gauge, as I get nearer to 2k, it goes from 12:1 towards 15, then 18/ too lean to read. This is with the 180 bleeds replaced wit the 120's and the 40 air bleed in the airhorn soldered shut too.

Reading through Jeff20b's Nikki thread he mentions that he's running 120 Primary fuel jets. I took a spare pair of 92's and a 1.2 mm drill bit, and made my own. I'd take a picture, but it's not obvious .3mm in pictures! Car did not like that! Back to no start. I think I'll have to order a set of 120 fuel jets now.

Qingdao

iTrader: (3)

I know its been said but it sounds like a vacuum leak. Are you using the thin intake gaskets from the manifold to the engine? I had problems with that and then moved to the thick blue striped W/P gasket paper. My issues were identical and it turned out to be an engine to manifold gasket failure.

If you feather the throttle can you get the car to rev up? Can you see fuel being delivered through the boosters when you do.

Since you are getting fuel at idle it would make sense that your idle circuit is fine. Because you are having issues getting fuel at high vacuum (part to closed throttle) it would make sense that the vacuum is pulling air from a leak (an easier source) rather than fuel.