Novak Conversions Jeep Wrangler TJ engine mounts

Fuel Pump?

Nk9

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Original poster
Supporting Member
Joined
May 9, 2025
Messages
7
Location
Colorado
Lots of good information on here pertaining to fuel pump issues, but I still cant help but think my issue is different. Its hot this time of year in Colorado and driven it plenty in heat without issue. This last weekend, Drove 45 mins to an event, let it sit in the sun for a couple hours and it hesitated but fired right up. Didnt think much of it. Drove it to lunch, fired right up after sitting in the sun. Halfway home, stopped to at the store and wasnt inside for more than 5 mins and it wouldnt fire no matter how much I cranked. Pump kicks on and tried to "prime" it a few times, no luck. Eventually I bled almost all the pressure off the fuel rail, fired first try and drove it home. It will fire early in the morning, but if I dont start it and try mid day, it takes the same treatment to get it fired up.

Heat soak would explain it running around and starting and stopping it, but not the sitting for exented periods of time. Its got 86k on it and a genright fuel tank, so I think its safe to assume the pump has been done before. Any ideas before I drop the tank? Fuel pressure gauge shows up tomorrow and that should really help confirm pump/check valve issue. I just cant wrap my brain around why bleeding pressure off solves it.

Thanks in advance. 🫡
 
You've got the right idea with the fuel pressure gauge. See if you can rig it up somewhere you can monitor the pressure readings while driving.

Everything is pure speculation without data.

-Mac
 
Update, 80psi running. Once shutoff, 3-5psi lost. At this point I may do a spark plug delete and fill it with diesel...

PLENTY of fuel. Any suggestions? Restriction in the line?
 
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Update for anyone experiencing similar issues. Pump regulator must've thrown in the towel. New Delphi pump assembly fixed it. 50psi and runs like a top.
 
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Novak Conversions Jeep Wrangler TJ engine mounts