Broke Down
If the engine cranks, it's not the nuetral safety switch.
If you have spark, it's not the cps. (the coil should be good too then)
If you have fuel pressure at the rail and see fuel exit the injectors, you have fuel.
Timing chain? Timing jump? (it should just run crappy though if it jumped a tooth)
Is there any odd noise while the engine is cranking? (have somebody looking/listening at the engine while you try to crank it).
Good luck brother. Keep us apraised.
Just keep thinking: Fuel, spark, air, and timing of all the three.
If you have spark, it's not the cps. (the coil should be good too then)
If you have fuel pressure at the rail and see fuel exit the injectors, you have fuel.
Timing chain? Timing jump? (it should just run crappy though if it jumped a tooth)
Is there any odd noise while the engine is cranking? (have somebody looking/listening at the engine while you try to crank it).
Good luck brother. Keep us apraised.
Just keep thinking: Fuel, spark, air, and timing of all the three.
Thread Starter
Junior Member
Joined: Aug 2010
Posts: 51
Likes: 0
From: Yuma
Year: 1992
Model: Cherokee
Engine: 4.0L
The engine sounds the same before it dies. I am thinking it may be the fuel pump going out. For a while I have had issues keeping pressure up when the engine is not running. It takes 8-10 seconds of cranking to reprime the line then it would start right up or I would turn the key on off on off multiple times or turn the key on and wait like a diesel. Maybe the pump is not pumping enough fuel.
Before I jump to that conclusion I am going to put in some additive and try to siphon some of it out.
Before I jump to that conclusion I am going to put in some additive and try to siphon some of it out.
Last edited by khenderson8x; Feb 20, 2011 at 12:56 PM.
Thread Starter
Junior Member
Joined: Aug 2010
Posts: 51
Likes: 0
From: Yuma
Year: 1992
Model: Cherokee
Engine: 4.0L
got some fuel from a different station and poured some in the throttle body. Started right up and ran for a few seconds even let me give it some gas without dying. Also tried out some starting fluid with the same result.
I tried resetting the computer as well.
I poured in a bottle of ISO HEET to maybe help get rid of any water in the suspected bad fuel.
This test leads me to believe that the fuel pump is bad. When I turn the key I can hear the pump turn on and it sounds like it primes the fuel line however with the key still on there seems to be no pressure at the fuel injectors when the little valve is on the rail. Does this mean the pump is actually not creating fuel pressure?
Also I can not seem to find this relay you were talking about.
I tried resetting the computer as well.
I poured in a bottle of ISO HEET to maybe help get rid of any water in the suspected bad fuel.
This test leads me to believe that the fuel pump is bad. When I turn the key I can hear the pump turn on and it sounds like it primes the fuel line however with the key still on there seems to be no pressure at the fuel injectors when the little valve is on the rail. Does this mean the pump is actually not creating fuel pressure?
Also I can not seem to find this relay you were talking about.
Thread Starter
Junior Member
Joined: Aug 2010
Posts: 51
Likes: 0
From: Yuma
Year: 1992
Model: Cherokee
Engine: 4.0L
well I changed out my fuel pressure regulator for $65 and still nothing. Did it need changed yes but was it the problem no.
There is no pressure on the fuel rail. I am guessing that it is the fuel pump. When I turn the key the pump turns on and primes the system or at least it sounds like it primes the system. Sounds normal like it has since i've owned the jeep. Could it be anything other then the fuel pump? I really do not want to change that out.
There is no pressure on the fuel rail. I am guessing that it is the fuel pump. When I turn the key the pump turns on and primes the system or at least it sounds like it primes the system. Sounds normal like it has since i've owned the jeep. Could it be anything other then the fuel pump? I really do not want to change that out.
☠ CF Sheriff ☠

Joined: Nov 2009
Posts: 15,197
Likes: 18
From: Aberdeen, MD
Year: 1995
Model: Cherokee
Engine: 4.0L HO I-6, 703 Injectors, Brown Dog Super Engine Mounts
well I changed out my fuel pressure regulator for $65 and still nothing. Did it need changed yes but was it the problem no.
There is no pressure on the fuel rail. I am guessing that it is the fuel pump. When I turn the key the pump turns on and primes the system or at least it sounds like it primes the system. Sounds normal like it has since i've owned the jeep. Could it be anything other then the fuel pump? I really do not want to change that out.
There is no pressure on the fuel rail. I am guessing that it is the fuel pump. When I turn the key the pump turns on and primes the system or at least it sounds like it primes the system. Sounds normal like it has since i've owned the jeep. Could it be anything other then the fuel pump? I really do not want to change that out.
Thread Starter
Junior Member
Joined: Aug 2010
Posts: 51
Likes: 0
From: Yuma
Year: 1992
Model: Cherokee
Engine: 4.0L
So am I to assume the fuel pump is bad based on the symptoms and my corrective measures or is there something I am overlooking?
Is there a test I could do to see if the pump is actually bad. I was thinking about unhooking the line that leads to the filter and having someone turn the key on to see if the sound I am hearing is actually the pump priming the line or just simply turning on.
Is there a test I could do to see if the pump is actually bad. I was thinking about unhooking the line that leads to the filter and having someone turn the key on to see if the sound I am hearing is actually the pump priming the line or just simply turning on.
Honorary Moderator
Joined: Mar 2010
Posts: 8,135
Likes: 16
From: Gilbert AZ/Las Cruces NM
Year: 1996
Model: Cherokee
Engine: 4.0 upgraded
an electrical test to verify the voltage and resistance tells alot....
just back probe the wires with a multi meter...
also when you do the fuel pump do the pressure regulator too
just back probe the wires with a multi meter...
also when you do the fuel pump do the pressure regulator too
Thread Starter
Junior Member
Joined: Aug 2010
Posts: 51
Likes: 0
From: Yuma
Year: 1992
Model: Cherokee
Engine: 4.0L
got it fixed
what a relief. Got a new fuel pump got everything together and tore into it without dropping the tank which was a relief since the tank was full.
Got everything apart and found that the hose coming off the pump on the back side of the pump had come off. What a bummer that a little hose ruined my hunting trip and left me stranded on the interstate. Oh well least its fixed and back on the road.
Thank you everyone for all your help. Learned a lot from this mishap.
what a relief. Got a new fuel pump got everything together and tore into it without dropping the tank which was a relief since the tank was full.Got everything apart and found that the hose coming off the pump on the back side of the pump had come off. What a bummer that a little hose ruined my hunting trip and left me stranded on the interstate. Oh well least its fixed and back on the road.
Thank you everyone for all your help. Learned a lot from this mishap.
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