Cherokee Help!!!! Fuel pump?

Rwentz

Member
Joined
Mar 3, 2011
Location
Greensboro
Ok so my 93 cherokee 4.0 died today, twice. When i got her home the first time i was almost positive it was the crank position sensor because she was dieseling, wouldnt start and when it did start she wouldnt idle . It was blowing smoke out if the intake and sputtering. I got her half way home and she started sputtering up a hill and cut, i called a tow truck and got her home , tryed to start her again and she wouldnt, bunch of my buddies came over and wanted to take a ride so i tryed to start it again after 3 or 4 hours of sitting, she started up real good, idled and everything. So i took her out for a joy ride just out on the roads, and she started sputtering and cut out when i started going up a hill but i pushed the gas pedal pretty hard too.
Idk what the problem is!!! I need help!!
If anyone has had this problem or knows what it sounds like please help
 
could be the fuel pump. I had similar fuel issues. Fuel pressure was looking OK, so we changed about everything else, nothing changed. Finally we noticed the FP gaugle would pulse a little under full load. Pulled the fuel pump and found thefilter sock laying in the bottom of the tank, and the rubber grommer that holds it in place had deterioated. Little chumks of rubber were all over the tank. Installed a new pump/sock assembly from Advance (despite every bad review I found on the internet), cleaned the rubber out of the tank best i could, and the problem is solved.
That was a tough one to diagnose, because at idle, it had good fuel pressure, just a slight flutter on the gauge under acceleration. the lack of power/bogging down while acceleration was very noticealbe thouhg. Mine never died while idleing, and always started right up.

Also check the vacuum line to the MAP sensor. While fixing my problem, we also found if the line was wiggled, it would leak, causing eratic idle.
 
What is your fuel pressure at the rail when running. I will say a majority o these issues is the cps. When it gets warm an cold it works intermittently.
 
if it's the fuel pump, if would not have started up again. since no fuel would be getting to the engine. I went through three of em in my cherokee in 5 years because i was too cheap to get a nice one. if it is it, get a bosch one, not one of those cheapy air tek/tech fuel pumps you will be lucky to make it last 1.5 years with an air tek
 
check your cps. check your cps. check your cps.

When they start to go bad they work intermittantly when heated up. Next time try dumping some cold water on it. wait a minute and try to start it. It's common on these things.
 
If its the cps and its going bad yea it will. But not forever but this is a way to tell if its the problem. It'll leave you stranded eventually.
 
Another way to tell if the crank sensor is failed is this: When it stalls and won't restart, unplug the coil connector and place a paper clip (or another suitable jumper device) across the 2 pins of the connector, then connect a test light to the POSITIVE battery post, while cranking the engine probe the jumper with the test light. If it flashes, the CPS is doing it's job. If it does not flash, the CPS is failed and needs replaced. In a nutshell, the signal from the CPS tells the PCM to ground and unground the coil. Make sense?
 
not to hi jack, but ive been meaning to ask a similar question. been meaning to give u a call jody. mine has these symptoms but at start up. It will hesitate and diesel after start up until it gets warmed up. after warm runs like a charm. but if i cut it off go into a store and restart it will do the same
 
cardudenc said:
not to hi jack, but ive been meaning to ask a similar question. been meaning to give u a call jody. mine has these symptoms but at start up. It will hesitate and diesel after start up until it gets warmed up. after warm runs like a charm. but if i cut it off go into a store and restart it will do the same
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I would check for a leaking injector if it were me. Can do that with a fuel pressure gauge or by pulling the rail off the intake with the injectors still attached. Cycle the key, look for leaks. That will be a good place to start.
 
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