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4 Wheel Drive/SUVs/Possible fuel pump problem

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Expert: - 5/12/2004


Question
I Have a 2000 Wrangler Sport with the 4.0 engine.  It has recently been difficult to start, and I do not believe it has anything to do with electronics. It has always started immediately and this problem came on slowly in the last 2 months.  I previously owned a 1997 and had the same problem. The 1997 eventually would not start at all and it was the fuel pump.  It seems almost the exact same problem.  I hate to spend 500.00 dollars for a internal fuel pump, if it may not be the problem.  Any advise on testing or is this typical problem when a TJ fuel pump starts to go bad.   Thanks   Randy,   Bethlehem Pa.

Answer
Randy,

This should be an easy one to troubleshoot.  This could be, nothing more than water in the fuel, a plugged fuel filter or plugged fuel injectors.  I would run a good grade fuel injector cleaner through a couple of tanks of fuel, and see if it helps.  Also, on the fuel rail, there is a valve (similar to a tire valve) that is used to test fuel pressure.  If the pressure is low, and it is due to a clogged, or dirty fuel filter, this can burn out a fuel pump if the filter isn't changed.  There are some sensors, such as the "throttle position sensor" that can cause a problem similar to this.  If the fuel system checks out ok, I would find a reputable shop, and have them run an electronic diagnostic on your Jeep.

  Carl

4 Wheel Drive/SUVs

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Carl Brandt

Expertise

Will discuss suspensions, lifts, lockers along with tire suggestions. Trail ratings and possible requirements needed for specific type of trails. Safety equipment and what you should carry with you. Certified off-road instructor. I am not a mechanic, and 4-Wheeling is a hobby, so if I can't answer a technical question it is due to my mechanical knowledge being related to vehicles that I have owned, or have worked on. I do not have manuals on all vehicles.

Experience

40 plus years of 4 wheeling in a variety of vehicles. At the present time, my major off-road rig is a 94 Jeep Wrangler with a spring over and a 1 1/2" suspension lift. This gives me a total lift of 7" or so. I have lockers front and rear. I have removed the track bars, and sway bar for maximum articulation. I am running a stock 2.5 ltr 4 cylinder with a Jacobs ignition along with a cold air high flow filter. It has 4.56:1 gears with a Dodge NV4500 transmission along with a 3.8:1 Atlas II transfer case. This gives me a final ratio of 105:1 in low gear/low range. Other vehicles I own, are a 96 Ford F-250 with a 6" lift, posi rear end, 36" Hummer tires, 5 speed with a fuel injected 460 ci engine, an 87 Samurai with an 8" lift, Ford 9" rear end with a spool, Chevy Dana 44 front end with an electric locker, 5.88 gears, 16% reduction in high range and a 6.5:1 low range with 35" Baja Claws, and a stock 2003 Grand Cherokee Overland. Trails I have run are the Rubicon (10 times), Dusey Ershim, Fordyce Creek trail, McGrew trail, several trails in Moab, Utah along with local monthly runs.

Organizations
Lost Coast 4x4's Cal 4-Wheel Corva UFWDA Blue Ribbon Coalition

Education/Credentials
Certified off-road instructor - Certificates in engineering/electronics

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