'91 PA Hard to start when warm

My PA has about 70,000 on an AC Delco replacement motor. It was stalling on me after idling, so I had it to the dealer to be checked out. From an earlier post I told them I thought it was the crank or cam sensor. They called later and said they were 90% sure it was the crank sensor. This was replaced and I have not yet had a stalling problem. However, the first start of the day is almost instant, but once the car is warm you have to crank it over for a long time to get it to start. The dealer looked at it, but couldn't find anything - they mentioned the possiblility of fuel rail problems but evidently didn't find any codes or anything. anybody have any good ideas?

Did the dealer check fuel pressure while the engine was warm? Fuel pressure problems will not set a code.

Try removing the vacuum line on the pressure regulator and see if there is fuel or the smell of fuel,if so the pressure regulator could be bad.

Yeah, the dealer checked the fuel pressure and said that it was good. Fuel pump, strainer and filter were just replaced a few months ago.

Have you checked the coils? Do you have the Delco or Magnavox ICM? Delco has the 3-coils mounted on top and all the ignition wires connect on the same side. Magnavox has the coils built in, and has the ignition wires coming out of each side.

His s/b the Delco/remy 3 piece pack and located over the alternator which get a little grumpy when the alternator dissepates ti's heat.