Most likely a fuel pressure regulator issue

ac_

ac_

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Hi guys,

I need some help finding a quality fuel pump and or regulator for my 98 TJ 4.0 15 gallon tank. I am pretty sure the regulator is bad. I get fluctuating pressures at idol with a gauge. It fluctuates from 51 to 55 so fast you can't barely see the needle. Also it doesn't prime with the key on. I have to crank it to get fuel pressure so it is hard starting. Once it primes it will start good till it sits again.

I think it is the regulator and not the pump. I am not sure if I want to replace the good working pump although I have to pull the tank to change the regulator. The problem is when I look on Amazon they only sell no-name brand parts and the all get bad reviews, Like only lasted weeks, or the gauge doesn't work yada yada yada.

Has anybody had any luck with Napa parts, or do you have a better solution? Any advice?

Thanks
 
With a working Jeep I think pulling the tank isn't too bad because you can drain the tank easily. I'd pull it and just replace that top thing. You might get it back together and find it didn't fix anything. It's $75 and a days work. That's what I'd do on mine if I thought for sure it was that top regulator assembly. I'd do Rockauto if I had time and not Napa but I'd let cost be your guide, it's all foreign crap.
 
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pagrey said:
With a working Jeep I think pulling the tank isn't too bad because you can drain the tank easily. I'd pull it and just replace that top thing. You might get it back together and find it didn't fix anything. It's $75 and a days work. That's what I'd do on mine if I thought for sure it was that top regulator assembly. I'd do Rockauto if I had time and not Napa but I'd let cost be your guide, it's all foreign crap.
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yeah, I cant really test the regulator because it seems to be working, just fluctuates at an idle and is hard starting. Also when driving it stumbles more so while cold but still when it warms up. The kicker is the fluctuating gauge. One time when I had an ignition issue a couple years ago, I tested the fuel pressure and it was rock solid. Now it has a weird fluctuation and doesn't prime with the key on. Needs to crank to actually get fuel pressure after it sits, so from all of the investigating that seems like the right place to start, But the reviews scare me. I do not want to be stranded. I hate that I can't count on my Jeep anymore. Would love to find a quality line of parts. I don't mind paying extra for quality, but it doesn't seem to be out there or at least that I can find. Thanks for the response.
 
With a pressure fluctuation and drain back I would replace the entire module, the Delphi pumps (over 6 years now) have been pretty reliable, stay away from crap store pumps but Spectra and Airtex in particular.

Be surprise if you had the 15 gallon in your Sport as 19 was standard at that point but it's possible. Either way use the 19 gallon pump.
 
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TJ4Jim said:
With a pressure fluctuation and drain back I would replace the entire module, the Delphi pumps (over 6 years now) have been pretty reliable so stay away from crap store pumps, Spectra and Airtex in particular.

Be surprise if you had the 15 gallon in your Sport as 19 was standard at that point but it's possible. Either way use the 19 gallon pump.
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So when my shows empty it takes 15 gallons to fill, but you are saying that I could shove a 19 gallon in my 15 gallon tank just in case? Will that change my fuel gauge if I actually do have a 15 gallon? Do you have suggestions on how to find out for sure?
 
Every Jeep has the 19 gallon tank. It's just the gauge and breather that are different, you'll find plenty of information about that everywhere. Many things can break at anytime and leave you totally dead in the water. Not planning for that in any vehicle is not wise.
 
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I just picked up the BOSCH 67655 assembly from Rock Auto. It arrived today!
It's pricy, but it has the best reputation of the pumps currently available.

IMG_20220119_204418_Greatness.jpg
 
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ac_ said:
So when my shows empty it takes 15 gallons to fill, but you are saying that I could shove a 19 gallon in my 15 gallon tank just in case? Will that change my fuel gauge if I actually do have a 15 gallon? Do you have suggestions on how to find out for sure?
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15 gallon fill up for the 19 gallon tank is very common, either way the 19 gallon pump will fit without issue.
 
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PFPJeep said:
I just picked up the BOSCH 67655 assembly from Rock Auto. It arrived today!
It's pricy, but it has the best reputation of the pumps currently available.

View attachment 303834
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Thanks for everybody's advice, and so fast too. This is the best community. I just ordered the Bosh from Rock Auto. it is an expensive bugger, but hopefully superior quality. This is solved thanks again for everybody's quick input.
 
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