Ok so I have 99 RWD 5.7 vortec and like i said, after i shutoff the engine i lose fuel pressure fast. I understand this could be the check valve in the fuel pump, which is fairly new, and the problem persisted after changing it. It could also be leaking from the fuel pressure regulator or the injectors. I'm just wondering is there an easy way to test this without having to remove the intake manifold? To be sure if it's the check valve or the FPR or injectors? I'm leaning towards the latter because I am running rich and having a semi rough idle... any help would be appreciated thank you
Slim
Slim