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Fuel pressure question

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Old Nov 21, 2011 | 11:14 PM
  #1  
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From: Wareham, MA
Year: 1988
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Default Fuel pressure question

so my jeeps been running like dog crap for a while, been having a whole mess of different problems since i pulled my tank out. i checked the fuel pressure today and the fuel pressure was at a pretty steady 20 psi through out the rpm range and at idle. ive read that 30+ psi is what the pump is supposed to put out and obviously mine is weak, but is 20 psi enough to make it run fine? could the problem could be elsewhere, like in the electronics/sensors? trying to eliminate myself from buying a fuel pump to find out it did nothing, i have very little money lately.
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Old Nov 21, 2011 | 11:20 PM
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what is running like dog crap? haha hard to answer with that being the only symptom. But 20psi is bad, and very low, cause it to sputter under load, and run lean which can miss and cause it to run hot. it does need a pump and that's a or the problem. you can buy just the pump and not the whole assembly.
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Old Nov 21, 2011 | 11:23 PM
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Originally Posted by Gorillaxj
what is running like dog crap? haha hard to answer with that being the only symptom. But 20psi is bad, and very low, cause it to sputter under load, and run lean which can miss and cause it to run hot. it does need a pump and that's a or the problem. you can buy just the pump and not the whole assembly.
heh, when you say it like that thats EXACTLY what its been doing... and im not sure but i tend to not like to mess around with that stuff of swapping out the pump, when i looked at it when it was out it SEEMED complicated but it didnt really look it over, i figure if im gunna replaced it, i just spend the extra 30 dollars and get the whole assembly. plus my friend said to do that as well if im gunna do it.
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Old Nov 21, 2011 | 11:28 PM
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If its a 30$ difference then defiantly buy the whole assembly, didn't list what year. On my 2000 its about 100-120$ difference between pump and pump assembly
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Old Nov 21, 2011 | 11:30 PM
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Originally Posted by Gorillaxj
If its a 30$ difference then defiantly buy the whole assembly, didn't list what year. On my 2000 its about 100-120$ difference between pump and pump assembly
yea, the pump is 70, and the whole thing is 100, just not looking forward to pulling my tank out again.
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Old Nov 22, 2011 | 06:12 AM
  #6  
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20 psi is NOT sufficient. Replace your fuel pump.

You don't mention the year, but for 87-95, you should have 31 psi at idle. Then disconnect the vacuum line leading to the fuel pressure regulator (be sure there is good vacuum at that line) and the pressure should jump to approximately 39 psi.

Do NOT buy an Airtex fuel pump. They are offered by many parts stores as a low price point, but this forum and others are full of threads of people that have had nothing but trouble with them. You may think you will be saving a few bucks until you have to do the job over again. Personally, I seek out a BOSCH fuel pump when I need one. They are the best in the business and worth every penny extra that you spend.
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Old Nov 22, 2011 | 07:14 AM
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From: Upstate N.Y
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Originally Posted by Gorillaxj
what is running like dog crap? haha hard to answer with that being the only symptom. But 20psi is bad, and very low, cause it to sputter under load, and run lean which can miss and cause it to run hot. it does need a pump and that's a or the problem. you can buy just the pump and not the whole assembly.
Does sound like the pump.

Last edited by 413maxwedge; Nov 22, 2011 at 07:19 AM.
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Old Nov 22, 2011 | 08:59 AM
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From: Eh infusion
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Hey sorry to go jack your thread dude but I had a fule related question and didn't wanna start a new thread. So when I drive and the engine is cold it acts like I take my foot off the gas a little then put it down again. It does this a lot until my jeep warms up to regular operating temp. then it goes away. You guys think it's the pump? An embolism some where in the line maybe? The injectors? My jeep has roughly 181000 miles on it. I haven't ran any fuel system cleaner through it. Will next fill up. If that don't work what do you think I should check? Fule pressure?
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Old Nov 22, 2011 | 10:43 AM
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Originally Posted by CherokeeChick
Hey sorry to go jack your thread dude but I had a fule related question and didn't wanna start a new thread. So when I drive and the engine is cold it acts like I take my foot off the gas a little then put it down again. It does this a lot until my jeep warms up to regular operating temp. then it goes away. You guys think it's the pump? An embolism some where in the line maybe? The injectors? My jeep has roughly 181000 miles on it. I haven't ran any fuel system cleaner through it. Will next fill up. If that don't work what do you think I should check? Fule pressure?
Check fuel pressure. if its bad it could be the pump or regulator. If its good then keep looking. sounds like a fuel/spark issue.
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Old Nov 22, 2011 | 09:44 PM
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Cool thanks
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Old Nov 25, 2016 | 06:44 PM
  #11  
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Year: 2000
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T. Having same issue. How do I check the fuel pressure. I'm a nubie so please forgive me. But man I love my jeep. I have done the plugs was suggested coil pack??
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