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1997 XJ 4.0L AW4 Long Crank Problem


NAXJA Forum User
NAXJA Member
I saw this topic/conversation discussed in the past, and being new to NAXJA, didn't know if and where I should start a new thread.
Anyways, when I start engine cold, it takes 5-7 engine turns to finally start. Upon first starting, it stumbles a bit. I can clear the stumbling by hitting the throttle a bit. Fuel pressure checks indicate check valve so will be replacing Fuel Pump Assembly at Fuel Tank. But as seen in previous postings, I am wondering which is best to do first? Swap out the Fuel Pump Assembly? Or Swap out the Injectors? I am the 2nd owner of the vehicle. When I bought the vehicle I was able to get print outs of previous maintenance by the previous owner. It was well maintained. But now at 266k it is starting to show its age. I have not yet seen a very clean way of testing injectors other than removing them all while recording their installation location and order, and sending them to a company out in Oregon for testing. Any advice would be very helpful.

I moved your thread to the tech forum, where it should get more eyes.

My 1996 seems to do the same thing when first starting, especially the starting a bit weird and being good after clearing it out. Anyways, it runs great once it is started, so i don't worry about it. I have always figured it is priming the system due to a bad check valve in the fuel system.
Mine has been long to start since the day I brought it home over 200k ago. Some people have spent much $ chasing the cause and never fixed it. As long as it starts every day, im leaving well enough alone.
If your testing indicates a failed check valve in the pump assembly, I'd do that first and worry about the injectors second.

Also, it'd probably be the same cost (or possibly less) to just replace the injectors as to ship them out/back for testing.
My 1998 has +290,000 and the original injectors, except for two that cracked, and were replaced with junkyard parts. If the injectors aren't broke, they don't need fixing.