INTERMITANT idle and stall problem

I have a 1992 lumina with the 3.1 engine. This problem is driving me crazy since it happens only half the time. 50 percent of the time I start the car and it starts fine and idles fine. The other 50 percent of the time it will not start without slightly depressing the gas pedal. Sometimes when it does start OK after 5 to 10 miles it will die if I let off the gas. An example, coasting down a long hill the engine will die (sometimes), other times it is fine. Also, stoping for a traffic light it will stall (sometimes). I first suscepted the TCC, but (4 speed auto trans 4T60), but most of my driving is on secondary roads at less than 40 mph, so I don't think the TCC is the problem or if it is, it may only be part of the problem. I have replaced the IAC and shot carb cleaner into the throat, and also replaced the fuel filter. I have read most of the posts on stalling and have not checked all the things suggested i.e. fuel pressure, vacuum leak, and various sensors, primarily because the problem is intermitant.

Can you please help?:banghead:

I must have offended everyone with my previous post since I got zero replys. If I did somehow I apolignize.

You might want to check the TPS voltage at the closed throttle position. Even though the ECM is supposed to "learn" the TPS voltage on start-up, there is a minimum and maximum allowable voltage.

If you have access to a scanner, you can also check the IAC counts at idle.

Blue Bowtie you da man. I replaced the Throttle Position sensor and the car runs great and idles like it should. I have drived only about 25 miles, but I think if it was going to die, it would have in this distrance (did in the past).

Thanks so much for you advice.

Now if you could tell me how to fix the "squeaking and groaning" in the rear end that would be great. I have the rear shocks and mounting plates replaced and that fixed a lot of the knock, but I still have squeaks and groans. Sounds like rubber bushings but I cannot tell which ones are making the noise.

Thanks again:)

Trihull, it's scary how absolutely similar our cars and problems are! Holy cow! I also have a 92 Lumina 3.1, and I've just recently been having problems with the car sputtering or dying when idling (going down a long hill, stopping at a stop light, etc.). I also have had a horrible squeaking noise in the back for years now. It gets so much worse when the weather is hot and dry. I noticed that the noise is actually coming from where the two bars that connect between the rear tires meet. A buddy and I tried putting some grease in this area, but it only helped for about a month and went back to squeaking again. Let me know if you find out exactly what it takes to fix that.

And as for my running rough / dying problem, I noticed that my IAT somehow got unplugged, so I think that may have something to do with it. Otherwise, I'm going to look into the IAC and the TPS. Glad you got your problem fixed!

Ok, I figured out last night that my idle air temperature (IAT) sensor had gotten unplugged. I had changed out the battery, which as you know on a 92 Lumina, is a rediculously difficult process. So it looks like in the midst of taking out the air filter housing to get to the battery, we unhooked the IAT electrical connector and didn't plug it back in. When I found it and plugged it back in, I had to drive the car around for awhile to get the ECU to adjust, but it doesn't die anymore. It still idles a little rough, but it isn't bad enough to kill the car anymore. I put in some fuel injector cleaner to allow that to clean out the fuel system. If it still idles rough, I'll look into replacing the idle air control (IAC) sensor and maybe the throttle position sensor (TPS).

I haven't figured out anything as far as the squeaking in the backend yet. Probably won't. It's not hurting anything...yet.

I know that this thread is a bit old....

the squeaking, creaking, moaning that you guys are hearing in the rear end is from the transverse mounted leaf spring that is in the back. There are supposed to be pads underneath the ends of the spring where it goes into a "pocket" on the outer edges. I replaced mine for like $20 or so and I haven't heard a sound since. My car is a 94 Lumina 3.1L.

You just have to bite the bullet and start checking those things they mentioned or start replacing parts. If you have high milage over 170,000 and just want to replace parts then, replace Fuel filter/in tank fuel pump, fuel injectors, chrank sensor! 3.1 Lumina's of that generation are known to have fuel injector issues at around 170,000 miles. You can get a set of six aftermarket fuel injectors for under $250 Summit Racing. New Delco or Borg Warner fuel injectors will cost you $100 each.