Lsmorin2004

I have a 1988 Jeep Cherokee Limited 4.0l. The problem I am having is my Jeep will not not stay running. When I have the key in the start position the jeep will run until about 3 seconds after I release the switch. At that point the jeep loses all ignition and fuel. I started with the ignition switch. Then the fuel pump. And then finally the crankshaft position sensor. After that I tried the ignition switch again just in case it was bad out of the box. I run a parts store it does happen. Anyone have any ideas? I am stumped. This has the reinex computer in it. I have not idea where to try next.

89Laredo

It loses fuel AND spark? Youve tested this?
Id say if it only loses fuel, look at the fuel pump resistor on the drivers inner fender.

But if its losing spark too, Im not sure where to look.

Lsmorin2004

Yeah did bypass the resistor as well. I'm stumped.

cruiser54

Over on the passenger side inner fender are a bank of relays. Try putting one of the other relays in the fuel pump relay socket.

You really need to click on my PINK LINK below and do Tips 1 through 5 ASAP.

CarterFamily88XJ

So I have a 1988 jeep Cherokee with the 4.0 and I recently was running wires from my electric fan over to the battery and relay center for ignition power. I had the negative into a pigtail for the battery. I ran the positive to the large OBD1 clip and inserted it to middle front hole. Started the jeep and the fan turned on and worked great. While I was securing the wires under the hood I removed the wire from the middle port. Started the jeep and noticed the fan wasn't working so I went to insert the wire like a damn fool with the engine still running. Once I touch led the wire to the port it sparked and the jeep shut off. Now when I turn it over it starts and runs until I let go of the key and it immediately shut off.
need some help and advice with troubleshooting on this one.

cruiser54

check the fusible links here:

CarterFamily88XJ

Can you cut the fusable links out to see if that's the problem

cruiser54

wiggle em. They'll be like a noodle where they melted.

CarterFamily88XJ

Thanks man that worked perfectly

cruiser54

found it?

CarterFamily88XJ

Yes sir one of the links wasn't connected anymore

Saudade

"Not connected" as in burned out? Did you replace it or just bypass it?

CarterFamily88XJ

I'm pretty sure the wire burnt out of one side of the boot.
Another question I have is my 4 wheel drive doesn't seem to engage or work properly.
I engage the lever into 4h and the front driveshaft doesn't spin freely but when I drive it doesn't seem to work. how can I check it and what would I need to fix?
Thanks in advance for the help and knowledge

cruiser54

Just do this. https://comancheclub.com/topic/17377-cad-fix-1/

CarterFamily88XJ

Would it be better to put lunchbox locker in front and rear or weld the rear?