1990 cherokee won't stay running

I have a 1990 Jeep charokee that will start but then stalls. I changed the fuel filter and checked that the fuel pump was working. I checked the fuel pressure at the fuel rail and that was fine also. I cleaned the TB also. I can give the engine a shot of starting fluid and it will run for a few seconds and then run really rough and then stall. I am thinking my problem my be a sensor but I don't know what to check out.
Any help would be greatly appreciated. Thanks

I have a 1990 Jeep charokee that will start but then stalls. I changed the fuel filter and checked that the fuel pump was working. I checked the fuel pressure at the fuel rail and that was fine also. I cleaned the TB also. I can give the engine a shot of starting fluid and it will run for a few seconds and then run really rough and then stall. I am thinking my problem my be a sensor but I don't know what to check out.
Any help would be greatly appreciated. Thanks

Check on drivers side inner fender there is a ceramic white block This is a fuel pump resister check to see if it has 12 volts
here is a site explaining
http://www.4x4getaways.com/XJBallast.jpg Dale :smokin: :grinno:

Check on drivers side inner fender there is a ceramic white block This is a fuel pump resister check to see if it has 12 volts
here is a site explaining
http://www.4x4getaways.com/XJBallast.jpg Dale :smokin: :grinno:
OK, Thanks. I did bypass this ballaster (as I was told it could be the problem and it really isn't needed) but it didn't help. I will check the voltage also.

OK, Thanks. I did bypass this ballaster (as I was told it could be the problem and it really isn't needed) but it didn't help. I will check the voltage also.

Also, is there a servo module for the fuel pump some where's that I can replace?

did you check the pump pressure with the engine running, did the pressure stay up when the engine died?

did you check the pump pressure with the engine running, did the pressure stay up when the engine died?
Yes, I did check the fuel pressure but the engine dies to quickly to check while it is running. The pressure was fine with the key turned on at starting time. It's like the engine is not getting fuel after it starts.
Maybe the computer isn't getting a signal after it starts? Is there a electric module that tells the fuel pump to keep pumping after it starts?

the pressure should stay for 30 seconds after the engine dies. There is a fuel pump relay located with all the other relays, maybe it is not staying on. I think the relays are the same , if they are you could swap the pump relay for maybe the a/c relay to test it.

the pressure should stay for 30 seconds after the engine dies. There is a fuel pump relay located with all the other relays, maybe it is not staying on. I think the relays are the same , if they are you could swap the pump relay for maybe the a/c relay to test it.
Actually, I did swap them because they all had the same numbers on them but I wanted to idenitfy which one was the fuel relay and replace it. They are not expensive and I thought it might be worth it. Do you know how to identify which one id for the fuel pump? I may have more then one bad one...maybe....hey, I'm reaching here...

my 89 did the same thing and it was a real mystery, the previous owner gave up and took a hot wire from the ignition and ran all the way back to the pump. When I bought it, I spent a couple weeks trying to figure it out. It turned out to be the signal wire for the fuel pump was grounging on the pass. side fender. I lifted up the whole wiring harness leading to the relays and the signal wire leading to the fuel pump relay, with insulation worn out was shorting out on the fender. I propped up the harness with a piece of wood , turned the key and everything was back to normal. Not likey you would have the same strange problem but worth looking at.

my 89 did the same thing and it was a real mystery, the previous owner gave up and took a hot wire from the ignition and ran all the way back to the pump. When I bought it, I spent a couple weeks trying to figure it out. It turned out to be the signal wire for the fuel pump was grounging on the pass. side fender. I lifted up the whole wiring harness leading to the relays and the signal wire leading to the fuel pump relay, with insulation worn out was shorting out on the fender. I propped up the harness with a piece of wood , turned the key and everything was back to normal. Not likey you would have the same strange problem but worth looking at.
Wow, thanks for the idea....I'm getting desperate here.

have to go to work now but I could check when I get home , then I will post, good luck.

have to go to work now but I could check when I get home , then I will post, good luck.
Thanks much, any help is appreciated.

Actually, I did swap them because they all had the same numbers on them but I wanted to idenitfy which one was the fuel relay and replace it. They are not expensive and I thought it might be worth it. Do you know how to identify which one id for the fuel pump? I may have more then one bad one...maybe....hey, I'm reaching here...


http://www.4x4getaways.com/XJRelays.jpg Here is a site that shows the relay Hope it helps Dale

http://www.4x4getaways.com/XJRelays.jpg Here is a site that shows the relay Hope it helps Dale
Thanks, I'll check it out...

Thanks, I'll check it out...
Is this web site correct? I can't get the page?

I just checked it. It works for me.

The CPS - crankshaft position sensor located on the bellhousing on the right side of the engine (if looking at it from the front). Souns like its gone bad or the wiring has gunked up.

the page should come right up when you click on it, I just book marked it for myself.

http://www.4x4getaways.com/XJRelays.jpg Here is a site that shows the relay Hope it helps Dale
Found it...it was .net that I needed.
Thanks, this is very helpful....

The CPS - crankshaft position sensor located on the bellhousing on the right side of the engine (if looking at it from the front). Souns like its gone bad or the wiring has gunked up.
Thanks, I will check this also.

Thanks, I'll check it out...
I found the site and replaced the fuel pump relay. It clicks when I try to start the Jeep and it starts and then it still dies.....
I am running out of ideas here....
Is there a sensor that measures the crankshaft movement? Someone mentioned this to me. If there is, where would it be, maybe it needs to be replaced also.
Thanks

The CPS - crankshaft position sensor located on the bellhousing on the right side of the engine (if looking at it from the front). Souns like its gone bad or the wiring has gunked up.
Thanks, someone else mentioned this. Do you have a picture or site that shows this? I'll try to find it tonight. I replaced the fuel pump relay but that didn't fix the problem. I will try to locate the CPS and check it out.

mine did the same thing the other day and it turned out to be the plastic egr valve . try unplugging that and see if it runs better.

new to this forum, but love my cherokee's :P uh, 2 ideas for yah, as i have come across the same prob 2x in my cherokee expierence... 1) sounds simple, chasis ground from battery? easy mistake... 2) TPS throttle positioning sensor, controll's choke/idle as well...

new to this forum, but love my cherokee's :P uh, 2 ideas for yah, as i have come across the same prob 2x in my cherokee expierence... 1) sounds simple, chasis ground from battery? easy mistake... 2) TPS throttle positioning sensor, controll's choke/idle as well...
Thanks for the ideas...I will check the ground. Where is the TPS located?
I just replaced the CPS and it runs better but still dies after a short period of time.

Thanks for the ideas...I will check the ground. Where is the TPS located?
I just replaced the CPS and it runs better but still dies after a short period of time.
I cleaned the ground and cleaned the TPS, the car will start but still stalls. Runs really rough like it's not getting fuel then stalls.
This is driving me crazy..... :screwy:

new to this forum, but love my cherokee's :P uh, 2 ideas for yah, as i have come across the same prob 2x in my cherokee expierence... 1) sounds simple, chasis ground from battery? easy mistake... 2) TPS throttle positioning sensor, controll's choke/idle as well...
Well, I replaced the TPS and the car starts and runs rough and then dies when idleing....now what? This is making me crazy... :screwy: