Fuel Pressure Problem

XJ_Jeeper01 · Aug 18, 2007

I'm pretty sure the issue I am having with my 2001 XJ Sport is related to there not being enough fuel pressure when starting it. I have not had a problem with starting since I've had it in '04 with 33k miles on it. It has 59k on it now. When I try to start it it acts like it's trying to turn over, but it won't until I give it gas. Once I give it gas, it starts up fine, but when I take my foot off the gas and it goes back to idle it stalls out. When I get it running and keep my foot on the gas to keep it around 800 rpms(idle) it doesn't try to choke out or sputter. After holding the engine at about 1k-1200 rpms for a minute or two the engine will stay running when I take my foot off the gas. And running around town, it runs like nothing is wrong. But once it sits for 15-20 minutes, I go start it and it does the same thing, stalling out at idle. Another thing is I tried to find the fuel pressure regulator and fuel filter and I couldn't find it. I don't know if Jeep changed things around for the 2001 models, but looking at the haynes manual for 1984-2000 models, I looked at where the fuel pressure regulator would be and it's not there. I am at a loss here. If anyone has any insight, I would much appreciate it. Thanks for your time.
-Matt

GrimmJeeper · Aug 18, 2007

XJ_Jeeper01 said:
I'm pretty sure the issue I am having with my 2001 XJ Sport is related to there not being enough fuel pressure when starting it. I have not had a problem with starting since I've had it in '04 with 33k miles on it. It has 59k on it now. When I try to start it it acts like it's trying to turn over, but it won't until I give it gas. Once I give it gas, it starts up fine, but when I take my foot off the gas and it goes back to idle it stalls out. When I get it running and keep my foot on the gas to keep it around 800 rpms(idle) it doesn't try to choke out or sputter. After holding the engine at about 1k-1200 rpms for a minute or two the engine will stay running when I take my foot off the gas. And running around town, it runs like nothing is wrong. But once it sits for 15-20 minutes, I go start it and it does the same thing, stalling out at idle. Another thing is I tried to find the fuel pressure regulator and fuel filter and I couldn't find it. I don't know if Jeep changed things around for the 2001 models, but looking at the haynes manual for 1984-2000 models, I looked at where the fuel pressure regulator would be and it's not there. I am at a loss here. If anyone has any insight, I would much appreciate it. Thanks for your time.
-Matt

its probably your fuel filter. change it and see if the problem persists. thats the cheapest place to start. it should be back by the tank inside the "frame" rail near the drivers side rear tire. after you change that run some good injector cleaner thru the tank, like lucas fule injector cleaner.

Hellbent · Aug 18, 2007

the fuel filter on that year is going to be a round metal canister sticking off the top of the fuel pump module. unfortunately, yes, on top off the tank. it also functions as the pressure regulator.

Thunder11265 · Aug 18, 2007

I'd say that the most likely culprit is the AIS motor. that is what controls the amount of airflow at idle. it's mounted on the back side of the throttle body toward the passenger side.

best way to swap it out is to remove the whole t-body fromt th intake, much easier to get to that way and you can also give the t-body a good cleaning (definately recommended when replaceing an AIS). make sure you clean out the passage that the AIS sits in very well. it's held on by 2 T25 torx screws if I recall correctly possibly a T-20.

XJ_Jeeper01 · Aug 18, 2007

Thanks all for your replies. This is very helpful information and it gives me a good place to start. I'm going to replace the fuel filter today and run some injector cleaner through and see how that does. Thanks again.
-Matt

Fuel Pressure Problem

XJ_Jeeper01

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GrimmJeeper

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Hellbent

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Thunder11265

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XJ_Jeeper01

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