Yellowjacket Fuel System

To those that missed my introduction, my CJ is a '79 CJ5 with 304 V8, T18 & J series D20.


Okay, so I named it Yellowjacket. Ol' Yj has died on me three times. I should add that it has Howell throttle body fuel injection. At first I thought the issue was ignition related so I replaced the Duraspark module. No joy. So the Howell tech and deduced I have a fuel delivery problem. Additionally the fuel pump was installed over 20 years ago and the PO mounted it way too high. The Howell tech said the pump should be no higher than halfway up the tank. This is how the system came to me. Way too much rubber fuel line as well.




So first some of the ever popular cardboard aided design. I chose this spot because anywhere along the passenger framerail would require much more fuel hardline to fabricate.


Which became this in heavy gauge steel.




Then a strip of metal to make the top flange.


Tacked in place.


Full welded. I'm bareing my soul here. My MIG welder was out of gas and I'm a terrible TIG welder. What's a boy to do?


The other three sides welded up.


To be continued...

 

I’m so jealous of you guys with fab skills.

rock on

 

Test fit. Launch is a go.




But too much pump exposed directly underneath.


Skidplate extension being added.

and welded with reinforcements.


Paint in simple gray. I like gray for undercarriage rather than black ever since reading Mark Donohue's book "The Unfair Advantage ".


Clean off the crossmember for a good pump ground wire connection. Remember, cleanliness is next to good electron flow.



Rubber baby buggy bumpers so the plate cannot vibrate against the gas tank.


Worm's eye view of the extended skid plate now covering the fuel pump.


And overall with new hardlines and minimal rubber hose.



TBC

 

One last picture of the fuel filter mounting.


I was waiting for testing before I posted in case this project was an involved failure. So far, so good. Two trips to Lakeport, about 16 miles each way. Thanks for reading.

If any of you hard-core Rubiconers think my mount will get terrorized on that trail, please let me know.

Joe out

 

Very nice!

 

Yes exactly. In front of gas tank, behind rear axle. The worm's eye view of the completed skid plate best shows off that position. The big gray thing behind the fuel pump bracket is an Aero Fab 26 gal fuel tank. It hangs down quite low. Good thing the PO bought the armored version cause there's Hella scrapes, gouges and dents in the bottom.
I too wondered about rear axle rearward movement. I need to get the Jeep on concrete and perform an articulation test.

Thank you.

 

Good work, but i'm a little concern about pump placement.

I would have gone on the side frame rail (like under the front seat) to get he pump as low as possible. You will have good feeding when the tank is full but as soon as it get below the fuel pump level you may have some problem.

Also having the fuel filter up there, it could bring some restriction the to gravity feed even more when you will be half empty.

And last thing, the bracket you made will probably ended up packing himself of dirt.

 

As noted, It looks like you have the fuel pickup at the top of the tank with the filter up high. That will create issues priming the pump after changing the filter being drawn thru before the pump.

I missed exactly what fuel delivery symptoms were had, but mine never liked being low on fuel. I was pulling from a typical carburetor fuel tank for a tbi conversion so I made this out of a boat filter, there is an extended "pickup" tube inside the filter on the outlet side. If there is any disruption to the fuel feed the volume inside the filter will feed the high pressure pump until the low pressure pumps can replenish the filter bowl. It does require a vertical path to return to the top of the tank.
20220115_230418 by Joe with a jeep, on Flickr