Hard to start, then runs terrific!

[robertoa1a]

I have a '96 5.0l xlt and for a while now have had a proplexing problem. When I turn the key. It will crank untill the battery almost is out of spunk. Then it runs great. I ran my diagnostics on it during start up and through the open and closen loop sesions with good results. The problem has gotten worse over the past six months. When I did my innital tune up a few months ago it included all spark parts and a fuel filter. On a '96 there isn't a wealth of perameters for diagnosis. Ya' gotta be smart. I did several fule pressure test but; how accurat is that on what may be a dying fuel pump?

If its the fuel pump: What? drop the tank and fixie? any percautions?

 

[James909]

You may be on the right track thinking it's the fuel pump. It sounds like the check ball in the fuel pump may be leaking allowing fuel to drain back into the tank. The next time you go to start it cycle the key from the off to run (not start) position several times and see if it starts easier.

 

[fenderbender2002]

If you haven't do so yet try replacing the three relays in the engine compartment. I had a similar problem and since I have replaced them it starts fine everytime now. Good luck.

 

[BrooklynBay]

Do you hear the fuel pump prime when you turn the key to the accessory position?

 

[James909]

Do you hear the fuel pump prime when you turn the key to the accessory position?

Do you mean the run position? I don't think the accessory position (turning the key in the opposite direction than you would to start it) runs the fuel pump.

 

[BrooklynBay]

I was referring to the position when the electrical system turns on right before you crank it. I guess you could call it the run position since it's right before the crank position.

 

[James909]

OK, that's what I figured you meant it was just a misunderstanding because I've always referred to the accessory position as the position behind the off position which doesn't run any of the powertrain electrical items just things like the radio.