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tju4u 02-08-2010 04:22 PM

fuel system problem?? Help me please!!
I-6, 4.0. Takes a few extra turn overs to start. found vac leaks and fixed replaced fuel filter and fuel cap. gas milage has gone down. also black around tail pipe. Any ideas??? I am stumped

Scottina06 02-08-2010 04:35 PM

Re: fuel system problem?? Help me please!!
well...the black means its running rich. Maybe a clogged injector or fuel pump? Could be any number of things with the fuel/air system

hemi.jon 02-09-2010 05:46 AM

Re: fuel system problem?? Help me please!!
With the I6 they have a common issue with the crank sensor causing the jeep to need a few more "turn overs" before it will start. its a $30 sensor that can actually cause your jeep to not start one day.

but that would not have a thing to do with you black around your tail pipe.. to test your fuel pump have someone sit under the jeep and turn the electrical on but do not start the jeep. have them listen to hear the fuel pump sounds like its priming well and sounds healthy. if for some reason its not priming right as you turn on the electrical you can hit the fuel tank with a rubber mallet and its usually a failing fuel pump temp fix.

Escape 02-09-2010 05:07 PM

Re: fuel system problem?? Help me please!!
On my 94 ZJ...Fuel pump, Crank Sensor and Water pumps are all well documented issues with the inline 6 4.0L

Fuel pump = Mine just died one day. Made a trip from Michigan to Florida, got to my destination and it just died in the drive.

Crank Sensor = Jeep would die randomly while driving or at an idle. It would just turn off so to speak and sometimes it woud start right back up other times it would take a bit. Easy fix hard to get to.

Water Pump = Went through 4 of these, one was bad right out of the box from the factory. Moderate fix once you modify the fan shroud, if it's the first time it sucks...make sure you modify the fan shroud!

The Jeep had over 180,000 miles on her before there were any of the above problems. She never left me stranded or got stuck. I used to do Search and Rescue so I can tell you it went places and through stuff no vehicle should ever go...and it did it with ease!

I just got rid of her last year (she was 15 yrs old with over 230,000 miles) and she was still going strong!


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