Fuel pressure too high - Fuel return line problems - JeepForum.com
 
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post #1 of 5 Old 08-08-2009, 07:55 PM Thread Starter
ChiroSean
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1994 YJ Wrangler 
 
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Fuel pressure too high - Fuel return line problems

Hey guys its been a while since I have been able to play with my jeep, but I just got back to it. I have a 94 YJ wrangler with a fuel injected 4 cyl. I have been trying to figure out the cause for the extremely high fuel pressure and poor gas mileage. I have narrowed it down to a blockage of the return fuel line before it goes into the tank. I took off the steel lines and was able to blow air through them (from back to front), when I blow air into the rubber line that goes above the tank skid plate the air wont go in. I looked in the service manual and can't find any good description of how that line is connected to the tank. Does this line go through the fuel pump??? Should I be able to blow air into it??? I have not dropped the tank yet but plan on doing that when I get back from vacation next week. Do you guys think I should just replace the fuel pump anyway while I have the tank down? Any information you guys can give would be a big help. Thanks.

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post #2 of 5 Old 08-08-2009, 08:19 PM
TSEJEEPERS
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Yes the return line goes back to the pump. At least on the 4.0L it does.
Mine had the same issue. It was pinched where the lines go through the cross member just before the tank. Follow the lines after the fuel filter, you will see the cross member they go through. After time and rust the area that the lines go through get smaller pinching the lines.
My fix was to pull the lines out, cut them and run metal lines through that area. Have not had a problem since.

93 YJ SOA 2" springs front, XJ springs rear w/main leaf added, High pinon 9 inch rear detroit locker front Dana 44 ARB 4.56 Gears, 36 inch Irok tires too much to list. www.mijc.org
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post #3 of 5 Old 08-08-2009, 09:07 PM Thread Starter
ChiroSean
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So did you have to drop the tank to do the repair? So if the rubber line was not being pinched then I should be able to blow air though it into the tank, or does the pump have to be running in order to allow the fuel to return to the tank? Should I leave the fuel pump alone or replace it if I am going to drop the tank anyway? thanks again.
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post #4 of 5 Old 08-10-2009, 04:25 PM
planedog
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ON mine the return line was bottoming out on the bottom of the tank. I cut it off at an angle and no more problems. You could see where this oine had been bottomed out for many years. I think the tank shrank and distorted over the years.
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post #5 of 5 Old 08-11-2009, 09:57 AM
TSEJEEPERS
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Quote:
Originally Posted by ChiroSean View Post
So did you have to drop the tank to do the repair? So if the rubber line was not being pinched then I should be able to blow air though it into the tank, or does the pump have to be running in order to allow the fuel to return to the tank? Should I leave the fuel pump alone or replace it if I am going to drop the tank anyway? thanks again.
Sorry but yes you will have to pull the tank. Maybe not all the way down. It is just too tight to get at the hoses.

93 YJ SOA 2" springs front, XJ springs rear w/main leaf added, High pinon 9 inch rear detroit locker front Dana 44 ARB 4.56 Gears, 36 inch Irok tires too much to list. www.mijc.org
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