03 Monte 3400 Struggles with starting when warm
 

So I've had this car for 3 years now, and as of maybe a year ago or less, when it gets warm it doesn't like to start. No matter what it cranks beautifully, but once it seems to get up to operating temperature and I shut it off, I have to just barely tap the gas, and it fires right up. I recently bought a new fuel filter, but it's been too cold to replace it. I've never replaced it since ive owned the car. I checked the fuel pressure before and it was about 45 psi. About a cigarette's worth of time later I checked and it wasn't any lower. I've never replaced any other fuel related parts. What should i check next? I clean my MAF pretty often, I replaced my oil pressure sensor, my spark plug wires, plugs. I'm not sure what else could be an issue. I've really never had a time I wasn't able to start it.

Assuming your battery, cables and starter are in good shape, my bet would be a dirty IAC motor/ pintle. You could take it apart and clean it, but as I recall it's only like $12 for new.

Forgot to add that I've replaced that too, first time i went to clean it, the whole pintle thing flew off haha. But where would i check voltage to? It cranks really nicely, just needs a tap on the gas pedal to start when its warm. I plan on replacing the grounds and power going to the starter and fuse box once the weather warms up.

After cleaning cables and connections, my next thought would be the ICM. If the heat sink lube (AKA-Thermal grease/compound) is dried up between the ICM and coils, the electronics overheat and stress out the ICM resulting in eventual failure.

As for voltage, the battery should read between 12.4 and 13.6 volts with no draw and should not drop more than a volt during starting, but more important is the amperage at the starter when cranked.

The guy at oreilly's said something similar, but in order to test the ICM (which apparently they could do there) they'd have to do it multiple times, to simulate it being warm like on the car or something he said. Is there anything else i can check out before ripping that off and having it tested?

It's not that hard to take off, but just curious, what type of plugs did you use when you replaced them?

A Seafoam treatment might also be in order if mileage is high.

NGK Laser Iridium 5599 plugs. But that was right around when i first got the car. Sometime soon i was gonna pull em and check out how they looked.

Those are good plugs and should last around 100,000 miles. Gap should be .060.

I never checked the gap when i put them in. Like i said, I'm gonna pull and inspect for any signs indicating any poor conditions, and check the gap. What would happen if the ICM was bad?

It will get harder and harder to start and run rough until it dies.