Yeah, that and a code 53. This is an excessive voltage in the charging system. Sounds like the fuel pump is getting too much voltage and the ecm is trying way too hard to hunt for proper fuel level since the votage readings are way off.
In open loop it is fine but once I am at operating temperature the engine surges to about 3000 and then drops to stall unless my foot is hard on the gas. Sounds like its running hard and if I let go, it just stalls out. Will not restart unless i stuff the gas pedal down.

The GM service manual says I should replace the alternator. You guys concur?

i am having a similar problem...

im running 16volts... (ugg). and its a brand new alt. but i beleave its the Voltage regulator on the alt. at first it ran great. 14 volts all the time. then it started running 16volts and sometimes it drops into 14... but will start bouncing back and forth, between 14 and 16. it's crazy...

but my volt light is on, and im getting a random back fire and nasty almost stalling idle. im thinking it's 1 of 3 things. fuel pump/filter, ICM, or cracked coil pack.

i know it's not the cat. i just replaced that, and although the problem went away for a while, its back again.


...

Same thing here. Could it be the alternator? I'm gonna be pissed if after replacing all these damned sensors and bullsh#+ it's the damned alternator and voltage regulator that's causing these problems.

Dm of mD


<img src = http://home.earthlink.net/~mgdm13/_images/JKrew-MD.JPG>

well heres the problem though. If the charging system had something wrong with it I would have the problem all the time right? I am only having the problem once the car gers up into operating temperature. This leads me to believe that it may be a sensor and once the ecm is getting input from sensors I am having a problem.
Then of course this is countered by the code 53 which is excessive charging system voltage. I have a digital dash so I cannot be sure what the actual voltage is doing but when I am driving the car and it starts giving me @!#$, I drive two footed, with extra gas pedal and my foot on the brake to keep it from stalling. During this, if I am stopped at a light, my battery guage drops down to about what I would think is 10-11v and jumps back up again when the car starts moving. So there is definitely a problem in the charging system, but why wouldnt I have this problem on initial cold startup?
A bad alternator is a bad alternator...why wouldn't It show these symptoms all the time?

ok so I swapped the alternator for a good one and guess what? same problem. It is really starting to piss me off. The damn car only has to last me another week at the most. I am getting a 97 sunfire (yes had to stick with j body) from a guy I used to work with. He bought it off the wholesale lot at the dealership for 1200 bucks and put new tires brakes ac clutch window motor and fuel pump in it. About 80k on the motor and hes selling it to me for a grand. Power everything and its got a $400 kenwood cd player in it. I am stoked. I just hope my cavvy can make it till then.

Maybe the old girl knows she's getting replaced by something 8 years younger and thats why shes acting up.


I cant figure it out.

nobody has a clue then? After looking at the car and the service manual I am wondering if the throttle position sensor might be faulty. That would explain a lot. I just jumped a and b again and I got a MAT sensor code, but that would not explain my problems. The MAP is on the same circuit but then again this would not make the motor surge like that. The TPS is what gived the ECM the reference voltage so I am going to start there and see what happens.
All this is really unimportant but since I am selling the car, I would like it to run properly so I can get some cash for it.

ok since i couldn't rely on you lugnuts to help me out on this one I had to wing it myself.

After I replaced the alternator I was still getting a code for excessive voltage at the ecm so I borrowed a tech 1 scanner and hooked it up. It was reading 25.68 volts at the ecm but the multimeter on the battery while running was showing 14.6 volts. Obviously the ecm was reading it wrong. It was also reading -38 F at the air intake (not always a bad thing) but the resistance test on the sensor was normal....so I narrowed it down to the ECM. I went over to Car Quest and picked up an ecm for $84 and did the swap. No more stuttering and crap....just crappy idle which should be fixed tomorrow when I do the idle relearn on it.

Problem solved.

Hmmm...ECM. Stupid computer. I knew that it could have been an option but wasn't sure. I guess all computer components go out after a while....

Dm