Weird lift pump problem - HELP!!
 

Hi folks,

Been having a weird problem lately that I can't figure out. I have random, intermittent zero lift pump pressure at startup. There's no real pattern to when it will do it but might be more likely to occur after running the truck and only shutting down for 15-30 minutes. When it does it, I do not hear the lift pump cycle when turning key to on position. In every single case, when I rev the engine, it will build pressure and run fine. May not do it again for weeks. Might be times where I have zero pressure every single time I go to start it in a day.

Truck is a 98.5, raptor frrp, pressure is good when acting normally...20 psi at idle, 16-17 psi driving

I have a feeling it might be a voltage issue but it is difficult to test voltage as there is no rhyme or reason as to when it will do this. Alternatively, might be the pump itself.

Any advice?

Thanks.