Really need help with Diag

[bobbywalter]

yeah....pressure regulator ....plugged filter....plugged sock in tank...or the pump is dying or wiring issue.

start with pressure regulator test. pull vacuum line

 

[GingeeShotz]

yeah....pressure regulator ....plugged filter....plugged sock in tank...or the pump is dying or wiring issue.

start with pressure regulator test. pull vacuum line

Should I do it with the pressure tester on?

 

[bobbywalter]

sure.

 

[GingeeShotz]

sure.

What should I experience when doing that? I assume there’s restricted flow somewhere. If the FPR is good. I assume filter. Then everything thing else. As if I’m dropping the tank I might aswell change it all

 

[bobbywalter]

i suspect a bad pump or very bad filter.

filter is next. fpr check is fast and easy and free....unless you bust the line.

but provides data. it should remain 32-38....we know it makes 38 psi just priming.

if the spring failed then when running it will lower the pressure out of spec and die.

 

[bobbywalter]

really it should be 40-45 koeo

 

[4x4junkie]

I love this truck but I’ve been having some issues with it. When I first got it, it ran fine for the most part. With the slight misfire at idle. Then sometimes on the freeway it would lack power until I floored it and it upshifted.

This part here about flooring it to get the power back really reminds me of an issue I had with my '94 that took me forever & a day to finally figure out what it was...
It ended up being the O2 sensors were fouled up with dirt (also a dirty MAF sensor).

Any chance that truck has an aftermarket oiled-gauze type engine air filter on it? (K&N, etc.)