So im sick of double cranking my truck so im gonna replace the fuel pump. I have a 99 cherokee XJ.

I work in a body shop and pulled up the R&I on the pump on ALLDATA. It says that the plastic cap NEEDS to be replaced when you replace the fuel pump. Is that REALLY necessary?

Also a tech at work has 2 Walboro fuel pumps, bran new. I compared the actual pump with pictures online(his pump is for a mustang) and the pumps themselves look identical, if i can get away with not spending $100 that would be great.
Has anyone else used a generic fuel pump? And is it really necessary to replace the cap/grommit?

Seversal years ago I used a generac pump when the damn thing went out in the wilderness.. About 90 miles away I found a generic auto parts house and they had a generic pump...which they assuered me worked fine on many models. I installed it in the thorny dirt where it went south.. As far as I know it is still in there working fine.
And NO! You don't have to install a new cap..
Big JIm <img src="/forums/images/graemlins/pfft.gif" alt="" />

hijack. the check valve or whatever its called that keeps the fuel from draining back into the tank when the jeep is shut off. is that in the pump itself or in the pump/sending unit combo? my guage is accurate so if i can get away with just a pump that would be a lot cheaper.

I don't know about the TJs, but in my CJ5 it is seperate from the pump...up inside the driver rear fender well. But then again my Jeep has a mechanical fuel pump.

The 4.0L does not have a fuel-line check valve. The FI fuel rail is pressurized once the ignition key is turned on and the fuel pump started.

There is a fuel return line that will allow fuel to drain out of the FI fuel rail once the pump is shut off.

For a fuel injected system to function properly, the tank must build an internal pressure and maintain it.

There is a check-valve that functions to block flow of fuel in event of roll-over or extreme off-camber when fuel could flow out the filler tube. The CJs have vapor recovery line connected to it. Depending on vehicle age, configurations are different. The valve is located near the filler neck.....

John... Its most likely the fuel regulator/filter (aka anti-drain back valve) In the top of the fuel pump is the anti-draniback assembly. This thing gives lots of Jeeps a hard start condition.
I have found new ones on eBay for as little as $30. Yeah it is a chore to replace them and many guys just go ahead and replace the complete pump.. But if the time and labor aren't a problem the price is cheap to stop the hard start condition.
The thing holds the pressure when the engine is turned off so the next start will have instant pressure. If one leaks the drainback causes a lack of pressure for several seconds during the restart. (depending on how long since the last start).
Big Jim <img src="/forums/images/graemlins/pfft.gif" alt="" />

It has been over 6 years since I had to replace one (on my 89 Cherokee).

My recollection is it was one unit with a separate screen filter.

Dropping an almost full tank to allow access to the top is a pain....

mine does not have a fuel return line. the guage will drop down to zero after like 30 seconds of the jeep being shut off. so big jim you think id get away with just replacing the pump? i have to do the key on and off thing like 3 times before it will start otherwise it cranks for a good 10 seconds. and it only pumps out at 45psi which is the lowest psi for spec.

As long as it doesn't seem to run out of fuel at high rpm, as if a filter were stopped up, I'd be replaceing the anti-drainback or if a lot of miles on the pump I'd prolly simply replace the entire pump assembly..
Just from your posts I'd think that would fix your problems.
Big JIm <img src="/forums/images/graemlins/pfft.gif" alt="" />

it doesnt run out fuel at high rpm. if i buy just the replacement pump instead of the whole sending unit i would also replace the filter otherwise the new pump wouldnt be under warrenty plus is only 7 dollars and i know the new filter would be clean. i do notice that when i start it when its cold it idles rough. it had a complete tune up about two years ago. could it be idleing rough because theres air in the system when the pump first builds up pressure?