Just picked up this car real cheap. Couldn't pass it up. The guy I bought it from says it will start and run for about 5 minutes, then just shuts off like you turned the key off. Only other mechanical problem is the a/c doesn't blow cold. Cosmetically, the clear coat is worn off in a lot of places and the drivers seat has tears and holes. Going to pick it up tomorrrow and start diagnosing it.

Welcome to the Bonneville forum.

Does the car restart right away, or do you need to let it cool again?

He says it won't start again until the next day.

What we need to know then is there spark when it don't start? If there is spark then check the fuel pressure. If there isn't spark, we will have to start testing things. Hmm, just had a thought. Is he using a valet key? I might be wrong but using that key only works for about 5 minutes, long enough to park the car.

I don't know. He has owned the car for a couple of years. He just drove it from El Paso,TX to Houston,TX last january when he moved here. He said about a week after he got to Houston it started doing this, so he bought another car. I don't know how many keys he has for it. I'll know more tomorrow afternoon when I get it to my house. I only paid $450 for it, so if I can't fix it, I figured the motor was worth that.

Update....got the car home today. Battery was shorted or something. It wouldn't take a charge so I put a new one in it and it doesn't stall anymore. Runs great.Looks like the only problem is the seized up a/c compressor and I can hear the coupler making a little noise. Not bad for $450.

Took it for a drive today. Sounds like I have an exhaust leak, the fog lights don't come on and the rear brakes are grinding. Going to check out those two things tomorrow. Also found out that the transmission pan gasket is leaking and the display on the radio isn't working. Also have a broken decklid torsion bar. That decklid is heavy.

Sounds like you need to pick one thing and fix it, then move on. I suggest starting with the brakes.

I think the brakes are ok. I've put a few miles on it now(8miles) and the brakes aren't making noise anymore. I think it was just rusty rotors from not being driven for 5 months. Rotors look fine now. I'm ordering a rebuilt a/c compressor and new drier & orifice tube tomorrow to fix the a/c.

Take a look at this first. Might be a good option that can save you some money.

https://www.gmforum.com/t278951/