THIS IS NOT FOR MY XJ... that thing still runs... lol

my buddy's 1997 XJ 4.0 is doing something weird...

the fuel pressure is fine at first... then randomly it will drop to around 18psi and barely run... shortly after is recovers...

he has installed 2 new pumps and cleaned out the tank...

he has also hot wired the pump to the battery...

and it still does it...

 

Did he just replace the fuel pump motor or actually the whole assembly. I ask because the fuel pump motor is driven by a fuel module. (mini computer that takes command from PCM to modulate pulse width or on/off)

If the whole thing was a cheap fuel pump then I would suggest you get a better quality.

If the fuel injectors are leaking then a quick test is to pull the fuel rail out with the injectors and do a test call key on engine off to see if raw fuel is leaking.

I will help you through this once I know what's up.