When the car sits idle for a few days, it is very difficult to start. It does turn over but won't start. Sometimes it will start after a long cranking session, sometimes it doesn't start at all. A complete tune up with new plugs and leads, fuel pump, filter change. When the car has been run, it starts normally every time. Is there anything else I should look at. I'm aware of the sticky fuel pump switches. Not sure if the new fuel pump is defective..

 

Possibly the fuel pressure regulator. To find out if the problem is the fuel pump, do a pressure test when trying a cold start. What brand of fuel pump did install? The cheap brands do usually fail early and have been known to have problems when first installed?

 

Thank You for your reply. I have a 7.4L/454 indirect injection, normally aspirated carburetor and I can't find the fuel pressure regulator on this engine. In the process of looking for the pressure regulator, I've taken the air cleaner and housing off to have a good look at the Carb. I had a helper try and start the truck when cold and no fuel comes out the injector bodies while cranking. Walked to the rear gas tank and could hear the fuel pump humming. Made about 3 attempts to start the cold engine while cranking about a minute or so. No fuel into the carb. the fourth attempt, fuel begain to spray from the fuel injectors to the carb throttle body, engine started. Again, when warm or has been driven, car starts normally. My question is should the fuel line remain full from tank while the car sits? Is there something else I should look at that may allow the fuel line to run dry, and the fuel pump just takes awhile to fill the fuel line up again, or is there seals or something else I should check on this, I believe, is a fuel starvation problem when cold starting. Thanks for your help in advance from this novice..

 

OK, MY BAD, I finally found out that my TBI injection fuel pressure regulator is in the back of the injector housing. Can anyone till me what is the normal fuel pressure should be on this 7.4L motor? How long should the fuel pressure remain in the fuel lines before it bleeds off? How long it should normally take to repressurize this fuel line if the pressure and fuel have drained out?