Fuel Pump Swap - Installation Problems

I'm trying to swap out a bad fuel pump in my 90 xj
So i went to nappa and got a fuel pump for what they said was an OE Replacement

Go the fuel pump out and low and behold the OE was freakin huge comparitive to the replacement that I have

My main concern is that the fuel pump will not mount rigidly in the mounting device that the OE was sitting in.

Here's the OE pump sitting in my hand.


The New one from Napa in the fuelpump mounting bracket thing


Any ideas? Is this something to be concerned about, or do I have to take it back and get a different part?

Any help would be greatly appreciated. Thanks.

Take it back. Take your pump with you to get the replacement.

Fuel pumps are a sticky issue on XJ's. Bottom line is that they fail a lot. Many people will say only go with a OEM pump. No matter which pump you go with, I recommend removing the tank, drain it completely and rinse it out so there is no crap in the bottom. No pump manufacturer will warranty the pump if you don't get a new strainer/filter/pickup and use it. While you have the tank out, check for rust on the outside and paint it with a rust inhibitor paint and you will save yourself a lot of long term grief.

Oh, by the way, be real carefull to get the connections the right polarity on the pump. There are two connections and they are of different sizes. Don't just trust the size to say which one goes where. I have run across different manufacturers that have them swapped. That is a bummer to get it all installed and not have it work. Lots of cussing and swearing.

I've had good luck with the Holley performance pumps and crappy luck with the generic Autozone and Advance Auto pumps. I would replace your fuel filter if it isn't pretty new. Think about it. If the filter is in any way plugged, it will force the pump to work harder. Pumps are such an issue, I have a pump I pulled off of a donor vehicle in a plastic bag under the back seat. Heck, I have at least one of every sensor on the vehicle in a bag under the seat. I haven't had to use them much but I sure have made a lot of friends on the trail with them.

I changed out the fuel pump on my 4.0 auto '90 XJ. Napa had two options, and one of the pumps was way to small. The second one fit a hell of a lot better, but not perfect. If I were to do it over again, I would just lay out the cash and go to the dealer.

Anyway, the NAPA part # you need is: P74155

Hope this helps

I just changed my '90 4.0 pump last month and the first one that I bought at Autozone looks like the one you got. It doesn't fit and I had to return it. I got one from NAPA that was even smaller, but it had a rubber base and top that made it fit the bracket perfectly. Since you have it apart, take the entire assembly in with you to make sure the new pump fits. By the way, they also sell a new ring to hold the assembly to the tank that made the reinstallation go lots easier. My old ring was pretty rusted and bent up from removal.

Thanks for all the info guys. I took the pump back and napa put the right one in my hands.

Where did you get the lock-ring thing, everywhere I try and talk to about it has been, "go to the dealer", "go to the junkyard" or "you need a new gas tank" kinda stuff. Mone of these guys are even willing to even LOOK at thier computer to think about getting that part. It's almost as if I say fuel pump and they shut the brain off or something and spew something that makes sense to them.

Any idea what the cost would be to get the new lock-ring and/or part numbers from stores?

Thanks again

I bought mine at the NAPA store that I got the fuel pump from. He had several hanging on the wall out front. It only cost $6. Take the old one in with you for show and tell.