I have a 98 cherokee with the 4.0 . You have to turn the key off and on a few times to prime the fuel lines. When you turn it off you can hear gas dripping back into the tank. Is this a pump issue or could it be the regulator?

 

I would say the fuel pump is starting to go south, the regulator just controls the fuel pump pressure to the rails and injectors.

 

^^XX2 on what the insane canine said.. I'd replace the inline fuel filter while yer at it (if applicable)

 

I had this exact problem on my 96 last year. It was a bad check valve which is inside the fuel pump assembly and cannot be replaced separately. I replaced the whole fuel pump assembly. Theoretically you could install an inline check valve between the tank and filter, but since it's likely the pump will also go bad soon the "easy" fix would likely end up costing you time and money you could save by replacing the whole thing at once.

Plan on replacing the rubber line from the tank to the filter and also the filter like previously mentioned. Since it's a 98 & you'll have to drop the tank to do it, I'd get a replacement lock-ring and o-ring for the tank so you don't have to drop it more than once. When I did mine, the lock ring, o-ring and rubber fuel line were all old and degrading and I was glad to have all new stuff so I only had to do it once.

Definitely run the tank as empty as you can prior to dropping it, and good luck! I found mine idled & accelerated a lot smoother with a new pump, and my fuel gauge was more accurate too; so that's an added incentive also!

 

The regulator and filter are combined and it costs 100.00. They list a fuel pump and two different strainers that are supposed to be used.

 

That sucks you have to drop the tank on the 98 model to change the pump!!! I have not had to change the pump in my 91..... YET! but it looks like i can sneak my pump out the front of the gas tank with out dropping it!!!

 

It looks like mine is in front too

 

It was easy to drop the tank