1990 cherokee won't stay running

[Johnk_56]

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

[Dale Aeppli]

Originally Posted by Johnk_56

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

[Johnk_56]

Originally Posted by Dale Aeppli

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

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.

[Johnk_56]

Originally Posted by Johnk_56

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?

[89ltd]

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

[Johnk_56]

Originally Posted by 89ltd

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?

[89ltd]

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.

[Johnk_56]

Originally Posted by 89ltd

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...

[89ltd]

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.

[Johnk_56]

Originally Posted by 89ltd

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.

[89ltd]

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

[Johnk_56]

Originally Posted by 89ltd

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.

[Dale Aeppli]

Originally Posted by Johnk_56

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

[Johnk_56]

Originally Posted by Dale Aeppli

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

Thanks, I'll check it out...

[Johnk_56]

Originally Posted by Johnk_56

Thanks, I'll check it out...

Is this web site correct? I can't get the page?