x57theman57x

Hey !!

New to forum !! Trying to start a 91 cherokee 4.0L !!

It's been sitting for a year !! It ran fine when it was put away !! It now turns over and fires with starter fluid !! Does not stay running !! No fuel delivery !!

I've changed the fuel pump & fuel filter canister still no fuel !!
Anyone have any other ideas ???
Can anyone tell me the location of the relays & fuses involved in this system !

Any thoughts or Ideas will greatly appreciated !!

THANKS !!!

MIKE M.

SeriousOffroad

Did you drain all of the old gas?

Check your PM In Box

x57theman57x

Frank !!
What you sent me is great !!
It is a bit technical for me but I am trying to figure it out !!

I have to locate the relays at this point and check them I think !!

The fuel should be fine !! The pump does not stay running to build up any pressure !! It makes and initial noise but does not continue to run !!

Any thoughts ,
Thanks,
MIKE M.

Retired F.D.N.Y. I'm glad there are some people out there that will never forget !!!

SeriousOffroad

Thank you for your service to the community. You are a national treasure as far as me and my family are concerned.

The fuel pump is only energized for 3 seconds upon start up. Once the PCM (computer) senses ignition it will then energize the fuel pump relay.

I'd suggest doing a Fuel System Leak Down Test (with a proper fuel pressure gauge) to confirm that you have 39 PSI at the fuel rail and that the pressure does not drop after the initial key on sequence.

rivercrazy

fuel pump relay should be under hood, passenger side in black box. There sould be a label in the cover than will tell you which one.

x57theman57x

Thanks for the advice so far !!

I have'nt done a leak down test yet (don't know how) !! I did change the relay & all the fuses are good !!
I still don't think the pump is running !!!

Don't know where to go at this point !!

Any other ideas out there ?????

THANKS,
Mike M.

x57theman57x

Question ????

Does anyone know if a bad C.P.S. (crank position sensor) will keep the fuel pump from working ???? The engine runs if I shoot starter fluid into the intake,but I have no fuel pressure !!!!!

Thanks,
Mike M.

rivercrazy

If it was the CPS you wouldn't get any spark. Do you have spark?

SeriousOffroad

You need a new fuel pump.

cwhitt87xj

i have an 87 xj and it sat for a year and a half and i got it running but the fuel pump keeps going out. i am currently on my 4th fuel pump and i have just about givin up. i have a cherokee for parts also and i got the fuses out of it and put in mine and it didnt do any good. i am getting low voltage to my pump also when its actually working. What do i need to do to fix my cherokee????? All advice is appreciated

wwxjwheeler

Low line voltage to your fuel pump may cause premature failure. Make sure your fuel pump relay has proper voltage in and out. If it has good input voltage and insufficient output voltage than your problem lies in the relay. If you are getting the same voltage in and out of the relay than your problem lies somewhere else in the circuit.

The relays that where originally on my 87 where not water tight and eventually I replaced many because of similar failure issues.

Don't waste your time and money replacing fuel pumps until you have good voltage and ground on your fuel pump.

wwxjwheeler

Additionally remember that rodents have a nasty habit of setting up homes in an engine compartment and nibbling on wires. Just a thought.

x57theman57x

HEY !!

Happy New Year to you all & your families !!!

I am the original "poster !!!

I still have not gotten the jeep running !!

Still have spark but no fuel !!
N0 rodents !!
Haven't done anything in 3 weeks due to Holidays & cold snowy weather !!

What is the voltage at the pump ???

I have already changed the pump relay,pump,cps,new battery & checked all the fuses !!

The truck ran fine when I stopped using it a year ago !!!:

As soon as the weather breaks a little I'll be back at it !!

Any new ideas or answers would be greatly appreciated !!

THANKS,
MIKE M.

jat2036

hopefully you have her running by now but if not (and if you still have her) you might check out my post.

I could not get my 90 cherokee to start and finally figured out the problem.....CPS and grounds

here's the link:
https://www.cherokeeforum.com/f2/sta...hlight=jat2036