AAAAAAAH! Phantom stalling again!

[ryan.hess]

I'm curious to everyone who's got a 3.4...... when it's cold, from a dead stop, when I press on the accelerator, it almost acts like a digital pedal rather than a linear one - like smoothly going from 0-20% throttle feels like 0%............10%..........20%, instead of 0...1...2...3...4...5%etc. I'm wondering if my TPS is bad and not showing up on my Freescan. Anyone else have the "digital pedal"?

[Lyle's GTP]

Ya, mine does that sometimes too.

Lyle

[ryan.hess]

hmm... and yours is broken too... Does anybody's working 3.4 do this?????

[Lyle's GTP]

Ya, But I have a new TPS and AIC in mine.

Lyle

[gpse3400]

Yeah I know what you are going though. Its a royal pain in the ass. All I can say is that I had the egr passage cleaned out to stop that egr code from popping up, replaced all the sensors, gaskets, and did a once over on my vacuum lines, pcv system , IAC, electrical harness, general tune up plus wires, and the timing checks out. It hasn't stalled in a good few months. There is one stupid thing it does when its warming up, the idle will just get alittle wierd approaching the point where it would be happy to stall, then it just picks right back up again.... I'm so tired of this engine's bs.....I swear if it's going to run like that I wish its was because I altered it.

[ryan.hess]

Have either of you replaced the crank sensor? That's next on my todo list after the TPS change... I noticed on freescan that my rpm sometimes jumps down to 700 for a split second and then back to "normal" 800rpm. The computer does nothing to counteract it, it keeps the iac the same, so might just be a loose wire, or it starts to act up when it gets warm. Anybody got a writeup on changing this?

[pocket-rocket]

Is the engine actually changing rpms when the scantool shows the "dip down" in speed? Only reason I ask is I have always been told if the CPS was bad, your engine wouldn't run at all. As for the digital pedal, both of mine go right up to the rpm that it stabilizes at depending on pressure on the pedal, but the 91 just does it faster then the 92 probably because of the headwork and cam timing.

[Lyle's GTP]

Just curious (knock on wood) was the phantom stalling thing just a pre 94' thing? I've never had the problem or anything like it.

Lyle

[blk92z34getrag]

Just curious (knock on wood) was the phantom stalling thing just a pre 94' thing? I've never had the problem or anything like it.

The bulletin was issued in 96 and states it's for 1991 - 93
LQ1 models, so I'm guessing so, I haven't heard complaints from anyone with a newer model LQ1.

[ryan.hess]

Is the engine actually changing rpms when the scantool shows the "dip down" in speed? Only reason I ask is I have always been told if the CPS was bad, your engine wouldn't run at all. As for the digital pedal, both of mine go right up to the rpm that it stabilizes at depending on pressure on the pedal, but the 91 just does it faster then the 92 probably because of the headwork and cam timing.

Well I was thinking a loose connection, bad wire, or something to cause an intermittant loss of signal from the CPS. While idling at a constant 800rpm, it sounds like it misses, and the rpms drop to 700-725rpm for a split second. I don't think the dash tach even registers it, it's so fast. My "digital pedal" only occurs when it's loaded, it doesn't do it in park. In case the injectors are at fault, are the 94+ injectors compatible with '93? What a headache.

[pocket-rocket]

The 94/5 injectors might be different due to being SFI vs MPFI (might be a different # rating). 96/7 injectors are a different kind for sure from what I have been told. Hopefully someone with this info will clue you in since I am not sure enough to say, "yes, they are the same."

[ryan.hess]

Okay, I just replaced the TPS and reset the computer... It seems to have a nice smooth acceleration now. The real test will be when it's cold, as that's when it seems to have the most problems with that. Have I fixed the stalling? Doubt it... but it hasn't stalled in a while Hopefully I'm not due

[Anonymous]

Doubt it... but it hasn't stalled in a while

When I took out my chip and put my stock one in, it didn't stall for a whole week. So I sent it to Ben, had him fuck with it, lord knows the day I get it back my car starts stalling with the stock chip. Pissed me off. I spent all the time/shipping $ cuz I was sure ti was the chip. But no, it was just my car fucking with me.

[Rit_z34]

solution to phantom stalling

So how's the car trouble going? I just humored myself by reading all your upteen billion attempts to fix the problem when it's already been stated. If you still need more proof do what I did w/ my 93 z34 (same engine) and take it to a "driveablity expert" at the dealership. Just tell them at service you want one to ride w/ you and see if if they have one that was around when your car was out. I was fortunate enough to have a guy that was old school enough and infact around, tell me that, "when these cars came out they had problems stalling. Some of them got taken car of right away but if the dealership managed to slip it by the customer, they stuck them w/ the bill of $700 fuel injectors ONLY MADE BY GM." Running out of parts to replace and already spending over $1500 in things such as IAC, plugs/wires, throttle control, and including bills from the dealership to tell me they couldnt find anything, I found the TSB (technical service bulletin) on it and took it to the driveablity expert. I would be willing to bet money that THIS IS THE PROBLEM from the thousand posts I've read here. Take it from someone who's posted hudreds of time just like you have and have been there buddy. Or, just keep posting and replacing useless parts. I've done my part here. Good luck!

-Rit

[ryan.hess]

Re: solution to phantom stalling

by the customer, they stuck them w/ the bill of $700 fuel injectors ONLY MADE BY GM." -Rit

So you're saying I have to replace the injectors with ones from GM? So far it hasn't stalled, and this rather infrequent occurance is hardly worth $700 to repair... But just in case...