Fuel pressure question
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Year: 1988
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Engine: 4.0L
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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Year: 2000
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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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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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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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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.
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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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.
Last edited by 413maxwedge; 11-22-2011 at 07:19 AM.
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Engine: The legendary inline 6, haven't done anything here yet
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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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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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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