[YJ43]

Hi everyone,

For a while now, my jeep has had a rough time starting up...usually have to crank on it for a few seconds. It was previously at a mechanic who couldn't pinpoint the problem, but did note that the fuel pressure was a little low. From researching, it seemed that maybe the fuel pressure regulator was at fault. So a few months ago, I went ahead and installed a new fuel pump, thinking it would solve any and all problems related to this. Initially after the fuel pump install, it started right up, however after a day or so, it went back to the same conditions, where it takes a little longer to fire up. However, once it's warm, it tends to fire up a little quicker. I talked to a mechanic, and he thought that maybe the CPS was to blame. Does this sound accurate? I would hate to throw a hundred bucks at a part that won't solve the issue. From searching, it seems that the CPS would only assist with engines running rough, having dling issues or stalling. The engine has about 73,000 miles.

Thanks in advance!

[Combatsylvania]

Does repalcing the pump also repalce the little anti-drain back check valve that is in the tank..

you seem to have all the symptoms.

[YJ43]

from what I understand it does...I replaced the whole unit. Unless there is something else I am missing...

[Jerry Bransford]

That doesn't sound like a CPS problem. When the fuel pump was installed, did they also install a new fuel pressure regulator assembly? They are often sold together but not always.

Within the regulator is an anti-drainback valve which is there to insure fast starts. It keeps the fuel rail and injectors pressurized but when it leaks, it allows the fuel to drain back down into the gas tank.

[YJ43]

Sorry, I forgot to mention, I installed it as one unit, meaning including the fuel pressure regulator assembly. I was installing a Kilby skid plate at the time, so figured I'd kill two birds with one stone. I can't imagine I screwed something up when I installed them...no lines are pinched or anything.