Volvo Repair: 94 940 turbo wagon, warm climates, turbo wagon

Question
Roger,  I have a problem with re-starting my car when the weather is extremely hot and the car is at operating temperature. I have this problem only in the summer (extremely hot) months here in TX. The typical scenario is that I have been driving for a while with the AC running and I stop and turn the car off.  Once I turn the car off it most likely will not even turn over.  I have to wait for 15-20 minutes before the car will start.  It usually starts right up after waiting for a short time.  Do you think that this is a starter issue?  

Answer
John, In warm climates like Texas and where I live in Florida this is a common issue.  2 things usually. One is the intank fuel pump has failed and 2 the fuel pump check valve is faulty.  The only way to check the Fuel pump check valve is to do a fuel pressure test.  Roger