Idiling issues

i have a 94 grand prix that has trouble starting when its cold. it starts, dies, then i have to restart it and let it warm up for ten minutes so it will actually run. If i don’t warm it up, even in mildly cold weather, it will die at a stop light or stop sign. the rpms also shoot up and down when idiling at times. Help!

Perhaps your Coolant Temp Sensor (CTS) is starting to flake out on ya. It’s easily tested by any mechanic w/ a voltmeter.

Also could be a vacuum leak. Check all the vacuum hoses and the air intake hoses.

I agree, the coolant temp sensor is the most likely suspect, but you may just need a throttle body and/or idle air control valve cleaning.

Those other suggestions are good, simple, things any novice mechanic can do. Also, check the tps (throttle position sensor) with a digital voltmeter. The tester should watch the voltage values, while the engine is running, for voltage spikes (shoot-ups), or, dead spots . With the engine not running, the tester would check the resistance (ohms) of the tps, by slowly, and smoothly, moving the throttle. Any flat spots, or sudden ohm changes, would be cause to change the tps. Of course, all of the other routine maintenance should be current; such as: fuel filter, air filter, spark plugs, spark plug wires, pcv valve, etc.