I have a 2001 WJ 4.0 that runs great, once it's started. It cranks a very long time before it fires up. But it never requires a second try, just a very long first crank. I just put a brand new fuel pump in and a brand new fuel filter which has a built in regulator. So I'm not sure what can be causing this. I've tried turning the key to accesories to let the system prime but that doesn't help. The only other thing I can think of is the fuel pump relay? And btw I have a p0455 vacuum leak code could this be the cause?

Thanks for any help!

I believe that code is often refered to as the "gas cap" code because it usually caused by a bad or loose gas cap. But seeing as you mentioned you just replaced your fuel pump I'd assume it may have something to do with that. Check to see if it was installed properly.

I'll be dropping the tank again this weekend to recheck everything and I just replaced the gas cap a few months ago, although it was with an advance auto cap and not the oem jeep cap. And I've checked all of these vacuum lines 5 or 6 times and can't find a leak anywhere. Still not sure if that would have anything to do with the slow cranking though...

Bump..

You have a vapor leak somewhere. You'll have to check all your vapor lines for a leak. I'd try finding an OEM gas cap before dropping the tank again to see if it helps. You could check your fuel pressure for ****s and giggles, but other then that I'm not sure what else to tell you.

BTW, the fuel pump doesn't run on accessory, only on run, and then only to pressurize the system. Once the engine fires, then it runs constantly. You may have a questionable CPS.

Thanks for the replies, I'll be rechecking all the lines this weekend for leaks. And Dave I do believe the fuel pump does run on accessories. You can listen to it turn on when in accessories...

And I replaced the CPS about a year ago. Possibly a cam sensor?