swapping an HO fuel pump into a non-HO truck's sender

[WiscoXJ]

So there's is always much discussion about the HO swap into mj's. More of The weird stuff comes when starting with a 2.5. One of the big things being the fuel pump. The 2.5 pump simply doesn't have enough juice to run the HO. What then are your options? Most will say you have to get a sender that will hold the 4.0 pump. But what about those that are using an HO donor and have everything? It seems silly when its all readily available. I worked for some time in a performance shop and when you slap a Turbo or blower on a car you need more fuel. Most people like to retain. The factory tank so we would modify the senders to hold massive fuel pumps or at times two. I applied the simple things we did to adapt a HO fuel pump into a 2.5 renix sender.

 

This small bucket at the base of the 2.5 sender prevents the HO pump from sitting as low as is needs so it has to be trimmed off. I let the sender sit for a few days to let the fuel evaporate before cutting on it



There are two tabs that hold the bucket to the return tube. Trim them as close as u can to the tube. I used a small cut off wheel and made sure the edges were smooth ish.





You won't be able to use that rubber bump stop at the base of the return tube anymore because it won't allow the pump to sit securely, but eye ball its as close to even with the base of the tube as you can and throw some hose clamps on! You'll have to put a new piece of hose to the top of the sender from the pump and splice the power and ground wires but that's easy.
 

[Marine1Texas]

Another option is a hi pressure inline pump that go's out side the tank. that way you just need to make the tubing in the tank solid. still able to use wiring .

We did this on my truck for a 2nd tank. We just used a relay and a switch on dash to use same wiring from truck to switch pumps.

[WiscoXJ]

Another option is a hi pressure inline pump that go's out side the tank. that way you just need to make the tubing in the tank solid. still able to use wiring .

We did this on my truck for a 2nd tank. We just used a relay and a switch on dash to use same wiring from truck to switch pumps.

Also a good idea :thumbsup:

I did this for a good option for those that have a HO pump but don't want to spend anymore than what it costs to get 2 hose clamps. I was wishing I hadn't got rid of my walbro 255 because I would have just ran that inline with the 2.5 and been fine.

[Pete M]

nice!  I'll move this over to the DIY forum in a couple days. :thumbsup:

[HOrnbrod]

Starting in 1991, the 2.5 and 4.0 engines used the same fuel pump in both MJs and XJs. Only the 90 and below Renix years used different pumps.

[WiscoXJ]

Thanks Pete! Ill post some more pictures of what I modified when you do that.

 

Hornbrod, I know, I just know there's many people doing an HO conversion that have a donor vehicle so why not use parts you already have. That pump is in a '90 2.5 sender. 95 pump

[WiscoXJ]

Pete I don't know if you can add these into the original post but here's what I did

 

 

This small bucket at the base of the 2.5 sender prevents the HO pump from sitting as low as is needs so it has to be trimmed off. I let the sender sit for a few days to let the fuel evaporate before cutting on it

 

 

There are two tabs that hold the bucket to the return tube. Trim them as close as u can to the tube. I used a small cut off wheel and made sure the edges were smooth ish.

 

 

 

You won't be able to use that rubber bump stop at the base of the return tube anymore because it won't allow the pump to sit securely, but eye ball its as close to even with the base of the tube as you can and throw some hose clamps on! You'll have to put a new piece of hose to the top of the sender from the pump and splice the power and ground wires but that's easy.

 

I have multiple high powered cars in the area that I've put fuel pumps in in this fashion and they all are still beating around town just fine

[JHS]

Great write up and idea. I am just about finished my 99 swap into my 88 MJ. I'm messing with fuel now. Both were 4.0. I am looking at my 99 fuel pump, and it doesn't have the mesh filter like your earlier one does. Should I buy a new 95 pump or is the factory 4.0 form 88 enough to run the single line system?

 

Thanks!

[WiscoXJ]

That pump should be enough for it