Fuel pump

[Krump_7]

Hi, im having issues with my fuel pump on a 98 gu tb45e straight petrol no gas. Have replaced the injectors with genuine new as the last lot shat them self. Doing a fuel pressure test, the manual calls for about 42psi of "key on no start" fuel pressure. I am only getting about 40psi can hear the pump working then itll drop right away and lucky to hold pressure at 20psi before fizzling out to 0. Takes a while to crank to get it to fire. When running the manual states 36psi, i am getting about 34 to 35psi. pressure drops to 0 almost immediately upon shut down.

Have checked for leaks at the injectors, by lifting the rail and having the key to on and no leaks. Have also run the car switched it off and pulled the fuel rail to check for leaks. Have checked for leaks as best i can along the lines.

Is this the fuel pump thats on its way out? Car has done about 340,000kms. Have never encountered a fuel pump issue before so dont really know what to look out for. Do they just die? Or do they begin to fail as above and then die.

Cheers for any help, have never posted on a forum so dont know what the rules for this stuff is aha.

Brad.

[Evo]

Hi mate.

Probably a good idea to pop over to the introductions section and put up a hello.

[Krump_7]

Have now posted in the "introductions" section.

[4bye4]

Don't know a great deal about petrol donks, but does this thing have a common rail with a pressure relief valve of some sort so that the rail doesnt stay pressurised ? If so could it be leaking.

[Krump_7]

Hi mate thanks for the input. It has a pressure regulator at the end of the rail on the return line side. Have tested this is ok by removing the vaccum hose while car is running, and the fuel pressure reads about 45 or so. So according to google that is ok ahaha, also no fuel coming from said vaccum hose when removed.

Cheers
Brad.

[Evo]

Have you tried removing the return line and turning the ignition on to see if you have enough pressure to push fuel out?

[Krump_7]

Just a follow up to this for anyone else who may come across this. Have replaced fuel pump. All is good now. 42psi "key on engine off" and 36psi engine running, vaccum line removed from fuel regulator psi jumps to 41. All to spec according to the manual, starts much better. Thanks for the input.

Cheers
Brad.