mjr45

I'm wondering if there is something in the thermotine circuit which may be contributing to the problem.

Thanks Sarah, I'm thinking I may pull the AFM and try to calibrate it per Atlantic Z and see what happens. The plugs are very sooty and the exhaust has soot around the tip, but after it warms up there is no smoke from the exhaust, gas mileage is not great but not real bad either. Vacuum on this engine is at 14 but thats up here at 9000' so corrected for sea level is in the normal range, besides if there was a vacuum leak it should be running lean, not rich. I've adjusted the AFM spring by 8 teeth to lean side with only minor improvement, I suppose it could be running super lean, but the soot marks on my garage floor kinda are against that, they show up with every cold start up. I know that the mixture is richened up on start up but it seems way to rich. There is a new CSV, CTS, Thermotine, injectors, FPR, EFI connectors, fuel and vacuum lines, timing is at 11°. I've checked and adjusted the TPS and the fuel cutoff in the AFM. The car runs well, but kinda falls off at about 4200RPM. I think that about covers it, I really appreciate the help. Thanks. Mike - - - Updated - - -

If the potentiometer in the AFM is 12-15% out of whack, would the potentiometer in line with temp sensor be able to bring it back to spec? I realize I'm talking about 2 different parts of the EFI, and the CTS potentiometer will rich up or lean the mix by increasing/decreasing resistance and is unrelated to the AFM, but in my total ignorance of electrical stuff I may be asking dumbass questions. Mike

If my AFM is out of spec, would using the 1K pot on the temp sensor make up for the out of spec AFM? Also, would turning the pot CCW decrease the amount of fuel the ECU signal would send, since the article seemed to want to add more fuel? I checked the resistance on my AFM according to the EFI Bible and got these Test #1 212 ohms, should be 180, test #2 112.4 ohms, should be "around 100", so I believe the potentiometer in the AFM is off. I'm not real sure how to "measure the injector duty cycle......and adjust the AFM spring so that the duty cycle matches the same as above." as stated in the Atlantic Z write up. Maybe ya'll can shed some light. Thanks. Mike

Great find, I hope you go through with bringing her back to life.

OK toady I checked the coolant temp circuit and got NO continuity on the wire harness, good, read 4.5ohms when really cold (38 outside and coolant not much higher) and 0.4 ohm after getting to 145° which by the FSM shows the sensor to be good. I'm thinking the culprit is the AFM, I'll pull it later and see if the vane is maybe bent, as I stated, I've already adjusted the toothed spring gear 8 or 10 teeth clockwise which should have really leaned it out and I don't think I should go any further with that. I'll run the tests in FSM on the AFM and that might give me some more info. I hate the idea of spending $200 for a rebuilt unit, but oh well its gotta run right before I sell it. The AAR is sticking which is causing the fast idle, so I'll clean it out some how, I checked today when it was "fast" idling after warmed up by clamping the hose on either side and it almost died out, so the AAR is not closing properly. I tapped on it with wrench and the idle dropped after each tap so its sticky. Thanks for the help. Mike

Fastwoman, the FPR, CSV and Thermotine are all new <6 mos old. All the rubber lines in the engine bay are new. I have suspected for a while that the AFM is the culprit, when running the tests in the EFI Bible some of the specs were off not real off, but not close enough to call it good. I've looked at the AFM (out of the car) and couldn't figure out how to take it apart to see if the vane was bent, looking at it with a light it looks OK but who knows. The engine did have a couple of front fires in the past so maybe its bent. Zed, I'll look at the BCDD section and see if maybe that's a culprit, it won't hurt to just disconnect the electrical line and see what happens. Also, Fig. EF 115 in my FSM shows the "fuel pipe removal." Go figure? Is it possible the ECU could be at fault on the rich running? I have a spare and just might swap them out as a trial. Thanks Mike

Zed, here are a couple of pics, one of the engine bay and one of the AAR, hope this helps with the quandary. No heater lines to the AAR. The engine bay pic is probably not real informative, sorry. Mike

Siteunseen, the BCDD shouldn't have anything to do with a fast idle after a restart, just when slowing down, but it might be that it gets stuck after the car is driven, I'll check on it. Zed, I'll post a pic of my intake later today, I tried to copy the pic from my FSM, but couldn't get a decent copy to post, I'll see what I can do later, because it is curious to have different diagrams from the same year FSM, curiouser and curiouser. I wonder of if a CA car has the heater and Fed models don't? I know the CA model had an EGR and the Fed model didn't.

Zed. mine doesn't look like that all, the lines in your diagram don't show in my FSM at all. Fast Woman, I'll check the coolant temp circuit tomorrow, the connectors are all new, but I don't remember if I changed the coolant temp sensor, I know I changed the thermotine sensor. The rich running has been a persistent issue, but the car runs great so I haven't been real concerned. Siteunseen, not real sure what your last post is about? Thanks for all the help. Mike

siteunseen, the AAR is less than 6 months old but I suppose it could be crudded up, I'll check, thanks.

Zed, I'll check the power line to the AAR, but there is no coolant line or a connection for one on the AAR which is the correct one for the year, no offense, the old had no coolant line either. As for fuel pressure numbers, I got 36.5 to 37 at idle. Just for reference, on a completely cold start(in the AM), the idle goes up to about 1300 then comes down after only a couple of minutes of driving, its only after driving for 15 minutes or so and then a restart after 10-15 minutes that the idle goes up and takes 1-2 minutes to come down to normal. Thanks.

Zed, there are no coolant lines running to the AAR. The new FPR should be adjusting the pressure, there is no fuel leaking from it when disconnected from the vacuum and a definite drop in RPM when disconnected. I'm not real sure how to check a drop in pressure from the FPR, I thought it was there to maintain a constant pressure in the rail. I've only checked fuel pressure with the engine running. Thanks.

Been gone for awhile and took the Z out the other day just for grins in the balmy 45° weather. Couple of issues, 1. it still runs very rich, lots of black soot from the exhaust and on the plugs. 2. after driving for awhile 10-20 minutes, shut her down and went to the store, came back out and started her up and the idle went to 1800 and very slowly dropped back down to normal. Things I've done in the past 6 months; adjusted the AFM to the lean side(ccw) 8 notches, new AAM, Cold start injector, injectors replaced about 500 miles ago, new FPR, new fuel lines, new filter. Probably some other stuff that I can't remember. Fuel pressure is right on. The rich running has been an ongoing problem but the high idle is new and doesn't seem to matter what outside temp is, did the same thing last fall when it was 70°. I need to fix this stuff since I will be selling her off in the Spring, don't want to, but need some $. Thanks.

There are some members up near you, Lone Tree Steve pops to mind, I live about 100 miles from you, but can maybe help a little. I've received tons of good advice and trouble shooting tips from the club, just ask and someone probably has the answer. Good luck with the project.

Not original, the original has a handle on the top, or all the ones I've seen do.

Nice looking Z, but not at that price with all the non-original stuff mentioned.

Have you tested the FPR? Its a simple check, it sounds like you are running out of fuel, so I still think its the fuel pump switch, where ever that might be in your setup, you get enough fuel to start and run for few seconds then the fuel pump kicks off. I agree with Zed, the injectors should click when you push the AFM vane. A carb system is goign to run you about $900 with carbs, intake manifold, fuel pump etc.

Never mind, got, amazing what a little freezing will do to make parts fit.

Well I got the new speedo pinion gear, oil seal and O ring, put them on/into the housing and guess what? The housing won't go back into the tranny! I've got it sitting in the freezer until tomorrow, any other suggestions as how to put this B***H back in will be greatly appreciated. Thanks. Mike

You are a madman! Can't wait to see the final product, keep it up.

Thanks guys for the help, I believe I know what to do now. I'll try the drill bit trick to see if I can get the oil seal out, now that I know what I'm looking for. Thanks again.

Thanks Carl, where did you find that? I got the O ring covered but not real sure about the oil seal part #60. MSA has a large and a small O ring, is the oil seal actually an O ring? I assume it goes into the pinion gear housing or does it go over the end of the cable? I looked at that thread and it has good pics of the parts all layed out, but none of them put together. Thanks again.

My speedo quit working the other and I noticed some oil around the pinion gear. I tried to loosen the speedo cable and the pinion gear just pulled out of the tranny because the little ear piece was loose and ahd turned. I know there are O rings and seals for the gear and the cable, but can't find and diagrams to show where they go, the only one I know for sure( also the only one I found) is the O ring around the gear holder. I need to replace the black gear as its sorta chewed up. The tranny is a 79 Z 5 speed and the cable is the stock 75. I need a diagram of some sort to know what goes where and I can't find it in the FSM. Any help would be greatly appreciated, thanks.

Sounds like the electrical gremlin struck again.