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Old October 23rd, 2009, 16:27
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x99j x99j is offline
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Join Date: May 2006
Location: ohio
Posts: 236
Re: Fuel Rail Failure after check valve

Originally Posted by XJTripp View Post
I have a 2001 Cherokee 4.0. The fuel pump check valve became ineffective and the thing took 2-3 tries to start every time. I basically wore a starter out before I took action. I put in an in-line check valve just like I had done previously with my 89 and it worked like a charm. Starts at the touch of the key --- for one day---. Today I was driving and smoke started pouring from the engine bay. Seems the fuel damper on the fuel rail sprang a leak and discharged like a shower head onto the intake. Luckily no fire.

I don't see how, but it must be related. Anyone else installed a check valve in their fuel line?

Possible theory - the pressure regulator is on the fuel pump, have I isolated it from the regulator and thus caused an overpressure condition on the fuel rail? Seems like when the pump is pumping the check valve would be open, right? So this shouldn't happen- right?

Other theory, the damper is just bad and I need to replace it and try again.

Anybody have a 2001 or 2000 that they added a check valve to?
i did the bmw check valve on my 99 when my xj had the same symtoms. well 2 days later i blew the fuel diaphram, just like you. when i stuck a fuel pressure guage on the rail, the fuel pressure climbed to 110 with the xj turned off. this mod does not work on 97+ xj's do to the redesigned fuel system! i had to get a new fuel rail from junk yard (25$) and a new fuel pump assembly. now i start on the first try! mike
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