Toyota Repair: 1988 toyota 22re mini motor home, fuel pressure regulator, toyota 22re

Question
I moved the toyota motorhome to stock it for a trip. Went to move the RV back and it will only start and die. My husband replaced the fuel pump, fuel filter, fuel pressure regulator, and air flow vent. He has checked all the fuses, all the relays and is now checking the vacuum pressure lines. Could the problem be in the vacuum pressure switches? Nothing has helped as of yet. I did have a cord plugged to the RV to charge the storage battery. It rained and threw a breaker in the house. Could that have anything to do with why it will start and then die? Possibly the electronic brain? He is stumped on this one. We have had no previous problems with it. Thank you for your help.

Answer
This is usually caused by a large air leak on the intake system, check for cracks or loose connections of the air intake hoses that connect the air filter to the throttle body or just check for any other large vacuum hoses that may have come off, remove the top of the air cleaner and check to see if the airflow meter door can be moved all the way open by hand and check for any foreign objects in the air filter housing