Heres my dilemma. I bought a 99 project truck that wouldnt start. The lift pump(in the tank style) wasnt working, so I replaced that. After cranking it over & over & bleeding the air out she finally started. (with only 8psi fuel pressure at idle) I drove the truck around for 15mins & shut it off....let it sit for 5mins & it wouldnt start. Im thinking its the vp because who knows how long the truck was driven with a bad lift pump & the no-hard start when hot problems, but why does it run so good when it does start? It purrs like a kitten, never stumbles or burps & pulls hard?
thanks
Doug

 

Check for codes. It very well could, just be loosing it's prime. Did you put a intank pump back in it? Recheck all fittings.

 

Could It lose its prime in 5 mins? Ive left it over night & it started right up?? I put a intank pump back in, I have checked all the fittings. But will go over them all again.

 

It will start right up cold, but not hot? If so then it's not loosing prime. What about the codes. Some 99's will and some don't, but try it, key on,off,on,off then on and watch your odometer. And the vp can go bad and not even though a code.