93 Lumina problem

I dont know very much about cars, so please help me. I have a 1993 Chevy Lumina with the 3.1 liter V6. I bought it from my mechanic who got it from a young guy who blew the engine somehow. So my mechanic replaced the engine with the one that I mentioned above and sold it to me for the price of the engine. It's a great car and I love it, but when I drive it for awhile and it's warmed up, it will die when I'm idleing at a stop light or stop sign. My mechanic told me it would fix itself, but after about 4 months when it didn't I took it to somebody else who reprogrammed the computer to tell the car to idle. That fixed it and it worked fine until now (about 3 months later). Now the car is doing it again. I'm just wondering if there is something I can do to fix it for good. Thanks!

Welcome Aboard!

You might want to check the condition of the Throttle Body. Dirt, gum, and varnish accumulation in the TB and Idle Air Control can cause stalling and/or poor idle speed regulation. There is also a rubber grommet on the top of the TB which seals a vacuum line or "T" fitting into the TB. These are known to deteriorate and leak over time, causing poor idle and a host of other issues.

Is your CHECK ENGINE light remaining on after the engine is running?

My check engine light will go on and off at random times, so I ignore it. By the way I hope you had a Merry Christmas, and have a happy New Year!

Scan the ECM for error codes. That may reveal something related to the problem.

First, you'll need to acquire a GM OBD I ECM Diagnostic Trouble Code Retrieval Tool (commonly known as a paper clip to most of our members). You’ll also need to have a Diagnostic Trouble Code recorder. I use a 3¼ x 5 ruled index card and genuine cedar #2 pencil, but I suppose any note pad and writing instrument will work for a first-timer.

With the engine and ignition turned off, locate the ALDL connector under the dash, just to the right of the steering wheel in the driver's foot well area. There should be a small rectangular cover over the access hole in the lower dash trim.

http://mysite.verizon.net/strey/files/ALDLPlug.jpg

Insert a tool as described above (paper clip) into the 'A' and 'B' terminals on the ALDL connector:

http://mysite.verizon.net/strey/files/ALDL.gif

WITHOUT STARTING the engine, turn the ignition to the "RUN" position. Watch the Malfunction Indicator Lamp (MIL) and it will begin to flash. This is also commonly called the "Service Engine Soon" or "SES" lamp. The first code will flash three times, and will usually be a code '12'. This is encoded by one flash of the lamp, a brief pause, then two successive flashes of the lamp. Each code will repeat three times, so you should see a "Code 12" flash three times. Any other error codes will follow in numerical order, and each code should flash three times. After all codes have been displayed three times, the "Code 12" will again flash three times, then all other codes will follow as described earlier. This cycle will continue until the jumper is removed or the ignition is turned off.

After you have made a note of all error codes, turn off the ignition and remove the jumper immediately. If you forget to remove the jumper and attempt to start the engine with it in place, you could damage the ECM. For this reason you should remove it immediately.

Once you have a note of all error codes, check this file for the decoding:

GM Error Codes.pdf (http://mysite.verizon.net/strey/files/GMError.pdf).

You'll need Adobe Acrobat Reader (http://www.adobe.com/products/acrobat/readstep2.html) to open/print the file.

Does a paper clip work on a '94 also? I know it worked on my '93 GA but wouldn't on a '94 GA. Sorry for the hijack.

For people who want a reasonable priced scan tool they are worth the money if you have problems.
http://www.levineautoparts.com/equus.html Look at the 3140 as it does both old and new.
http://www.ntxtools.com/ Search OTC scanners. Some are over $3500.00 plus require yearly update

Does a paper clip work on a '94 also? I know it worked on my '93 GA but wouldn't on a '94 GA. Sorry for the hijack.
Got 'er figured. Paper clip will work with a '94. Will those obd scanners give abs codes also?

Edit: Just noticed H terminal is for anti lock brake.

Some 1995-95 models were transitioning toward OBD-II at GM. The jumper does no good on these models.

Some 1995-95 models were transitioning toward OBD-II at GM. The jumper does no good on these models.
Ok, for those interested my car is an early 94 (built 08/93) so it is OBD-I with 12 pin connector and codes can be checked with a paper clip. The later '94's may be OBD-II with a 16 pin connector and need a scanner to check codes. Now that I know this I'm almost looking forward to getting a code to see if I can fix it.:grinyes: