91 Lumina stalls- even tried a psychic :-)

[Jeremy-WI]

anniette, you mean the torque converter clutch wire.

[Kooterskkar]

IF it's acting up when cold, it can't be a computer related sensor, as teh car doesn't use any of them until it goes into closed loop when the motor is warm. I still say it's a fuel pressure regulator, and its a pretty simple job. The only difficult part is getting to the two small coolant hoses on the bottom of the throttle body, other than that, its gravy, shouldn't take more than 45 minutes if thos two hoses really fight you

Wait, what? NO, the TPS always directly controls the amount of feul that the engine consumes when given throttle. Cold or warm it doesnt matter. How would you drive anywhere when the engine was cold if every sensor was disabled until it got warm? You couldn't, you would open the throttle and with no reading from the TPS it would get pumped full of air and stall.
And to replace the FPR you dont need to completely remove the throttle body. Hell, you dont even have to remove the cables from it. Just remove the bolts and pop it loose from the plenum. For now though I wouldnt even mess with the FPR. The TPS is a 25 dollar part. If you dont want to spend that much, rip one off of a car at a local bone yard. Theyll prolly want 5 bucks at most for it. If that doesnt change anything, now you've got a spare if it ever does go bad. Remember to do an ECM relearn after you put the new one in.

[tmcsherr]

I really feel for you guys. I have had this '97 since it was new, and have never had a day's trouble

Lucky guy Jeff! Keep those fingers crossed!

My first guess is probably the Ignition Module. But if you have already replaced it, I believe maybe the problem is computer related.

tblake, thanks for checking with your buddy....I don't see how you can come to teh conclusion that it has anything to do with the ignition module (no, I haven't replaced it) if it has great spark....am I missing some connection here?

That completely rules out the O2 sensor right there.

Guys...so we can eliminate the O2 sensor? I'm assuming because when the engine is cold the whole egr loop system is not operating...so it couldn't be anything related to that...is that the theory? (even though, I think SOME of the other sensors DO operate when cold....have to, richtazz)

So....with the O2 and other related EGR sensors ruled out. (?) It seems like it's coming down to the TPS, Fuel Pressure Regulator, or ECU. I really don't want to spend $900 on this thing, so the computer is a last resort (anybody got a line on cheap computers? can I use a junkyard unit and just swap chips? can I use one from a more recent year?)

The TPS is an easy fix. The FPS looks a little tougher...gotta take off the intake manifold to get to it...any problems there?

I really appreciate all the brain time you guys have given this. It's still acting good (wouldn't ya know...when ya WANT it to go bad, it wont!), I think I'll start collecting these parts and have them ready though. From the looks of the posts on this forum, if these parts aren't bad now, they will be soon anyway.

[richtazz]

go with the fuel regulator and TPS. They aren't too expensive, and are easy to replace. IF you have a 3.1, the regulator is under the upper plenum on the drivers side, and is pretty easy to do.

[Kooterskkar]

Yeah, the hardest part about replacing the FPR is popping the injectors back into the manifold. Be sure to get new o-rings for the injectors if you do replace the FPR.

[tmcsherr]

Yup, my mistake...meant to say under the plenum, not under the manifold. It didn't look like I had to take the injectors out though (looking at Chiltons)/ it looks like the FPS sits right on top, nice and pretty, and once the plenum is off, just have to twist the FPS out without removing injectors......?????

[tblake]

Your ignition module could work fine one day, and then all of a sudden crap out. Or for that matter coil packs also. The only way you know for sure is to make sure all the cylinders are firing when the car stalls out, and idles like crap. Sounds to me like, maybe one of the 3 coil packs might be starting to fail, causing 2 of the 6 cylinders to misfire. Someone Correct me if I'm wrong with my theory. Good luck.

[tmcsherr]

tblake: thanks, but as I've said many times here, the car idles fine, just cant accellerate. I have to admit, I only checked the spark to one plug, but it was fine and the engine isn't missing at idle...I'm going to rule out any ignition related problem.

[Jeremy-WI]

I have to agree with tblake on the ignition control module. Another idea that I haven't posted earlier is that the harness could be chaffed through between the ECM and the ignition control module grounding one of the wires(tan/black and/or white wires) causing the vehicle to stay in module mode for timing advance

[Kooterskkar]

Yup, my mistake...meant to say under the plenum, not under the manifold. It didn't look like I had to take the injectors out though (looking at Chiltons)/ it looks like the FPS sits right on top, nice and pretty, and once the plenum is off, just have to twist the FPS out without removing injectors......?????

If only it were that simple. The feul rail is in two peices with the FPR being the connecting "bridge" ill say, for lack of a better word.

[jeffcoslacker]

Originally Posted by Kooterskkar

Noooo, never say that, you jinx yourself. Hey if you take good care of it nothin should go wrong for a long time. But I hope you got some money somewhere to drop on that thing. Once you hit 100,000 miles theres that much more of a chance that something will go wrong.

You are right about the jinx, but my car can't read, so as long as I don't say it where it can hear me, I should be OK. I have always used synthetic oil, changed at 5-7 thousand miles, good fuel from reputable stations, Slick 50 every 50 thousand miles (twice now, due again), coolant change once (when I did the water pump), I keep the engine bay clean, giving it a degrease and hose down every spring, followed by a chaser of WD-40 on all electrical parts and connectors. This has been my regimen for all my cars for years, have gotten over 300,000 on some before problems became excessive.

Had a 1982 Mazda 626, sold it at 323,000 because the syncros in the gearbox were getting very tired. The guy still drives it to work everyday, pushing the half million mark now. Poor old girl burns two quarts of oil a week now, but still sounds great except for some piston skirt slap at idle.

[tmcsherr]

tblake and jeremy:
I don't get it..............if it idles good, doesn't miss, has plenty of spark...how can it be anything to do with the ignition?

[tblake]

ya, if it idles fine, probably has nothing to do with ignition. I missed that part when you said that the first time. Fuel Pump, regulator, throttle position sensor, O2 sensor. Check these.

[Kooterskkar]

I have always used synthetic oil, changed at 5-7 thousand miles

Seems to me the drain intervals for most synthetics are around 15 - 20,000 miles. Thats waht i've read at least. Thats seems like kind of a waste to change it that soon. You just have to change the filter after about 5000 miles. What brand do you use? Im tryin to rebuild an engine to drop in my dodge. I figure after I get done ill run syntheic in it, and im lookin at a few brands but havent met anyone else who uses them yet.

[Jeremy-WI]

If certain things don't happen between the ICM and ECM the car will be in module mode, which means it will stay at 10 BTDC timing and should idle fine, but overall performance will suck.