yorgie

i have a 1999 jeep grand cherokee i have replaced the fuel pressure regulator the fuel pump and the fuel lines the problem is it still has high fuel pressure ( 60 psi ) what could the problem be ? thanks for your time

Bustedback

Does the engine run? The spec is 44 to 55 psi, so whats the problem? Too much fuel pressure will not cause the engine not run.

jnicewan

What is the jeep doing to make you want to look at fuel pressure? What guage are you using and have you tried another guage. 60 PSI is right out of the spec on the higher end, its hard to believe there is a problem and to see the fuel pump hold a constant 60 PSI.

When you said you replaced the regulator, you are talking about the filter/regulator assy right? When you replaced the fuel lines, did you replace the return line from the filter/reg to fuel tank?

yorgie

it blew the muffler off it and i was told by the muffler shop there was fuel getting in the exhaust system causing the muffler to blow and all the lines have been replaced including the return and new fuel pressure regulator and pump
Thank you

jnicewan

Well I would not suspect fuel pressure first. Does it run ok? Does it smoke (dark grey or black)? Fuel in the exhaust system can blow up a muffler but many other things could be the culprit, ignition system, components or timing are a few. If it was running rich enough to dump enough fuel into the exhaust to blow up a muffler, it should be running very rich and very poorly.

Bustedback

Guys that work at muffler shops are good at mufflers, but not so good with other systems on a vehicle.