The check ball goes bad in the OEM units allowing fuel to drain back into the tank.

 

Sup speedy..

Yea but does that mean the mechanically the pump is on its last leg.. or will the pump run just fine.. but i'll have to prim it before starting?

Under WOT i get no stumples or hiccups.. but traction is a b!tch lol

 

If I remember right (which I never do ), then the pump is fine. I think the check valve is only for priming the car initially. We will have to get someone to double check that though...

 

actually, not quite, the check valve is there to keep the fuel in the lines from draining back to the tank, if the fuel drains out of the line, the 2 second prime of the pump isn't enough to get the fuel in the line and up to poressure, plus, it keeps the pressure up for starting

 

What about when the car is running? I would think if the pump is running and constantly pumping gas just fine, then it will have enough pressure to not worry about. Or does it effect the pump no matter what?

 

The check ball will go with the flow - which ever direction the higher pressure is on. you wont see any ill effeect once the engine is running.

you could verify this with a long fuel pressure guage taped to the window of your car (never run a fuel line into the car) and watch it as your driving.

this is handy if the fuel pump can not keep up at WOT, sometimes only way to tell for sure.

 

Why does everyone suggest taping it to the window when you can get a second person to slam on the gas in park, while you watch the gauge , I never understood that theory...












and don't say crap about how "that's bad for the engine and blah blah blah", it's one flooring while the car is in park, it's not like a train getting derailed or anything.

 

the fuel pressure needs to be checked under load, and anything in park/neutral is not under load, a smaller part, is that in park, you are not subjecting the pump to try to push against thee inertia of the fuel in the lines trying to push back into the tank(a concern with weak pumps, but usually not considered on street cars)

 

Well atleast you did not give me crap on revving it in park

I'm also learning about this fuel pump stuff, I have not had to deal with any of the fuel pump related stuff. Only FPR and injectors.

 

Car runs just fine.. no high rpm stumbles. I'll just live with priming it until its time to upgrade the fuel system.