My girlfriend bought a 94 lt1 a couple days ago and has been having some issues with it. It was really hot the day she brought it home, around 41 celcius outside and the car heated up. it got up to about 228 and the fans came on and it dropped to 215. It started running really rough though. The next day I got up and took it for another drive and after about 20 min of city driving it had heated up again to that temp and then cooled off. I guess these temps are normal from what i read. It started to run rough after 20 mins of driving. This morning it got up and drove it for about 20 mins and the temps all seemed normal or even a little low although it is much cooler out today. After driving it for 20 mins and parking it and went into a store for 15 mins I came out and started the car and again running rough, stuttering and it was cold this time. I dove the car home and by the time I made it back to the house it was running good again. Not sure where to look first. Rad fluid and oil look great and the top rad hose heats up nice as the car warms. I also made sure the intake was clear and it has a newer K&N filter. Any help would be greatly appreciated as she is having a meltdown over it.

 

Since you just bought it, I would do the normal tuneup stuff, plugs, wires, 02 sensor, etc. That could very well take care of your problem. If not, check for codes.

 

It sounds like you have a problem once it heats up and you go into closed loop. You are not running hot that sounds normal. She has a OBD-1 car so get someone like at a auto parts store to see if there are any stored codes. It sounds like a sensor to me. Don't just throw parts at it.

 

Even if there isn't a code, it can still be a sensor. If you find someone with a scantool, have that hooked up when the problem starts and see the actual sensor readings.

 

Doesn't the 94 have an obd2 plug? I read online it does. I checked under the dash and it has a 16 pin plug.

 

IIRC that is correct.

 

It has a 16 pin plug but OBD-II was not implemented. Like I said it is OBD-I. Be careful of what you read on the inter web!!!

 

If its happening in closed loop the first thing I would suspect would be a sensor, the first sensor I would suspect would be the O2 sensor or sensors.The O2 sensors are supposed to be changed on a specified mileage basis and a lot of times the owners never change them...You also mention it has a K + N filter, make sure the previous owner didn't over oil it and foul the MAF.. I would hook it up to a scan tool like suggested and see whats going on....WW