My dad has an 89 suburban that will not start when warm. He thinks it is running "too rich" or the "choke has died on it from what it sounds like, it will stall unless it has a little gas when you put it in to drive..however once it gets up in the RPM band everything is fine. Good power at WOT, etc. It also idles perfectly once started after the intial "rich condition" is fixed it seems.

I want to make sure the advice I gave to him was relevant and if there is anything else I'm missing:

- Inspect FPR and vac line to insure it is working and no fuel is getting into the vacuum system.
- Check for spark when condition exists

I have a scantool we can hook up to the car..anything worth looking at?

lets not forget the truck works fine when its cold, fires right up and idles perfectly.

Check the MAP sensor, since it doesn't have a MAF because it is TBI, the PCM depends on the MAP to measure manifold pressure. I would hook the scantool up and check it out.

OK will do. anything else we should look at?

Hmm..... It wouldn't be a bad idea to check the timing, and stuff like that.

keep in mind, it is 100% heat related. I'm trying to determine what would cause a no start or hard start condition when warm.

OH! This is a problem related to the Fieros also. If the ignition module in the distributor gets too hot, the car will run like crap, and will be hard to start when it is hot. If it is the original, I recommend you pull it and have it tested, the heat may have weakened it some. Also clean the holddown bolts for the the module, as those are what grounds it.

This is most likely fuel pressure related. You will probably find that it'* the fuel pump. Recent visits to a truck forum helped me diagnose a similar problem on mine.

Something to do with the fuel pump heating up causes the check ball in it to stick and therefore when you start up cold, all is well. However start up warm when the ball isn't in the right place and you don't have any pressure in the lines.

My TBI 2.5l would have trouble starting when it was warm. The distributer replacement fixed it after the mechanic exhausted all the fueling possibilities.

I'd also put my money on the ignition module.

Very common problem with GM HEI.

Have you checked the fuel pressure? I'd put money on the fuel pressure regulator.