My son's car will start in the morning or after it has been sitting awhile, but it won't start, say, if he shuts it off to run into the store, or get gas, etc. If he waits a few minutes, then it will start. It cranks, but won't start. Thanks.

We need to know, “wuzz happening” when it don’t start. Does it have spark or not, or does it have correct fuel pressure, or not? Also, does it have any codes?

i'm having the same problem with my 93 pa .. i have changed the o2 sensor cause thats the error that the car gave but the next day same thing... i have spent a ton on the last breakdown changing the fuel pump, plugs ,wires, coils, module and filter....even the mass airflow sensor.. im wondering what could cause this problem as well.. thanks in advance:disappoin

Both sound like the early warnings of a CPS (crank position sensor) failure! You need to hook it up to a scanner, when it won't start and check for RPM's. When it is cranking, you should see 200-400 RPM on the scanner for it to start and to verify CPS operation.

Thank you. I will have my son check the spark and fuel next time it does it when he's home. For the codes, does he have to take it somewhere and have the car repeat the problem so they could tell him the codes, or is it something he can do himself? To the other fellow who posted with the same problem, please post if you figured out what the problem is - thanks so much!

If your son has ACC (auto climate control), you can check the ECM codes with that, or he can check the codes by following the instructions in the link below;
service engine soon (http://www.geocities.com/dann8785/serviceenginesoon.html)