I just picked up a 96 Lumina with a 3.l and when i went to start it, nothing. I turned the key and nothing, so I wiggled the key and it started. Ran good. After about 6 starts in about an hour, it would not start. It would turn over and catch a little, but then nothing. Let it sit over night and started up. Drove it for 15 min and had the same issue all over. Tried starting it about 5 hours later and it started fine, but the A/C pump would not engage. Driving it home it just shut off. Got it refired and got it home. Also while driving it ,it stumbled so I wiggled the key and it took right off. Got to a buddys to scan it, the motor ran rough and quit. Got it stared after 10 min. We put a code scanner on it and found no fault codes. The A/C worked then. The fuel pump does cycle, but we did not have a fuel psi gauge to check it. After recharging the A/C it idled great. Both fans came on. Drove it home about a half of mile and it started running rough and it cleared itself out. The key is very worn out ,so I have a new one in order. Any Ideas?????

 

Sounds like a passkey problem. Is the key "loose" in the ignition, or the ignition switch "loose"?

 

It was very loose and the chip was worn and loose in the key. I was on my way to get the key and made it about 2 miles and it shut off. Left the car and got the new key and it stared right up. Going to go for a cruise now. Thanks for responding. Will post later if it corrected the problem.

 

Put on 40 miles and ran great. Got home and it was idling rough and quit. Will not refire. Waiting for fuel pump to cool to see if it starts. Looking like a fuel pump replacement.

 

Do you have a check engine light? The 3.1 and 3.8 have issues with injectors. Don't just replace the pump without checking the fuel pressure. I have the identical car as you. If you have a CEL read the code if you can, if the code is a P0300-306 it is misfire that last digit is the cylinder number.

 

The check engine light is not on and we checked codes last night and found none. We are going to check the fuel pressure next. Tried starting it about 5 min ago with no luck.

 

Sounds like fuel pump

 

Check fuel pressue and I have none. Pump does not come on. Checked all relays and fueses. No issues there. Power to everything. Time to change the pump.

 

You might jumper the contacts to the pump from the pump relay, if it doesn't come on, then pump. If it does, then probably relay. Also the fan relay is next to the fuel pump relay, swap them, and see if it comes on.