1993 Cutlass stalling and sputtering

I have a 1993 Cutlass Supreme with the 3.1L and the four speed electronic automatic transmission (PCM 16149396). The car will occasionally flash the check engine light on when I let off the gas, then not respond to the gas pedal and stall. A check of the codes reveals no codes (just 12 over and over again). I found a page from KEM (http://www.cardone.com/English/Club/Products/ELECTRONICS/Protech/Tech_Bulletins/pt52-77.asp) that described the problem exactly and said it was a problem with the computer having bad solder joints. I replaced the compuetr with a working one from the wreckers (or at least they claim it is ;) ) and after warming up the same problem occurred.


One thing I did notice is if the car is having a fit, stalling and sputtering in Park, if I shift it down to first and sit there, it runs perfectly smooth and doesn't even hint at stalling.

Anybody have any ideas? Thanks in advance.

Bumping this because I am still at a loss. I am on computer #3 now and it still does the same thing. Only causes a stall when the car is warm, shows a check engine light before stalling yet reveals no codes. I don't want to throw money at this willy-nilly, but the idea of buying another coil pack has come up. Shouldn't that give me a fault code though? If I have a grounding problem, shouldn't I see other symptoms?

Help :(

A faulty coil pack will cause two cylinders not to fire, but your car will still run. It will not throw a code.

What you have sounds like heat soak. You might need a Ignition control module, some auto parts places will check yours for free, or if you are so inclined you can check your own. This link shows you how:

http://members.fortunecity.com/slade901/automobile/Ignition_Troubleshooting.htm

The other component subject to heat soak is your crank position sensor, and when the car heats up if your cps is faulty, your car will stall.

The module is the device located below the coils, right? I seem to remember changing one of those on a car (along with the coils for the hell of it) but it gave me a code to point me in that direction.

My father has the car today, as the battery died there last night. After changing the battery the car will still not start at all, even cold.

I will try out that test procedure and see what I get. I have a wrecking yard run to do this weekend for my Cavalier, so I will see if I can scavenge another module and crank sensor anyways.

Thanks for the help.

I changed the module and the car starts and runs now, but it still stalls. I didn't drive it on the highway, but during city driving it stalled a couple of times at a stop light. This time around it was no warning. Just like I shut the ignition off with no sputtering. It started again right away and I drove it home.

I still have no codes. I just realized I forgot all about the damn CPS :( Is that type of random stalling they type of thing you would see with the crank sensor, or wil it just go all flaky like before and not want to run right at all?

I had a car that would do almost the same thing as yours. Mine ended up to be a faulty fuel pump. Basically the pressure in the fuel line would drop and the car would stall. It would only happen in hot days and after driving 30-45 minutes. The car would restart right away and you are able to drive it again for another 20 minutes or so and it would stall again.

Just to make sure, did you change the PROM on the computers when you swapped them? It might not solve the problem, but if you didn't use the original prom, things might not be responding right. I kind of question the fuel pump theory because you say it runs fine under acceleration, but I can't say to rule it out.Best bet on that is to get a pressure gauge and connect it to the schrader valve on the fuel rail and watch the pressure. let it run and get a reading, then open up the throttle up to about 2k or so and let it off. If you see a sharp pressure drop, then you should change the pump.

I will get on that fuel pressure test.

As for the crank sensor, should those just slide easily out of the motor? I went to steal the one off my Cavalier to try it, and it got jammed in the motor and broke. Guess I gotta buy at least one now.

For the PCM, I did not change the prom from any of the modules. The car seems to drive and shift normally right up to the point that it stalls. Can I change the PROM even if it is a different build (i.e AUBU vs BJCS - those are from memory and may be wrong)?

The current condition is that it runs fine until it gets warm, then just shuts off like someone switched it off. If I 'two foot' drive the car (keep the RPMs up in neutral while stopped) I can keep it from stalling. The symptoms seem to have changed since the first fault, but in the end I still end up with a car that stalls.

IF CPS doesn't do it then check fuel pressure. Don't rule out MAF either. Get a scan tool to see if your TCC locks/unlocks.