88 Cherokee, Will fire, but PITA to get running!!!

klock89 · 02-10-2010, 09:38 PM

Okay, So Ac was installed by some shop in '90. Was held in by brackets... And power connected to + on Battery... AC Pump recently siezed, snapped belt, so I removed AC Pump, And replaced belt. It ran good for 3 days, then started to sputter really bad, Took it to the store and it wouldnt even stay running to get me home, Had to keep firing it, and it was acting like it was getting no gas, Changed Fuel Pump, and It has the same issue still, Except now I have an electrical issue, I have to wiggle ECU harness for a while to get it to run... otherwise fires and dies. I can tell when it will run because I have a ticking from a relay under the dash. When i get the ticking the fuel guage goes all the way to full and continues going til it has made a complete circle. then goes back to normal, but when the relay ticks, I hit the brakes, and the dash lights light up and the fuel gauge does the same thing until I release the brake. I replaced the relay... Cleaned all grounds.... And it even does it with the ECU unplugged.

Any thoughts?

**jeepdavetj** · 02-11-2010, 02:13 AM

Um, are you sure its the ECU? I mean it shouldn't run at all if you unplug that. Anywho it sounds like your problem is at the connection you are movin around. So I would start with the connections there.

klock89 · 02-11-2010, 03:53 PM

No No... It is the ECU I am wiggling the harness of... but it will fire and die, and I get the ticking from the relay under the dash(replaced and still does it), With the jeep off, I wiggle the harness a little, and turn the key til the fuel pump comes on to see if I have a ticking, if I do, I turn it off and continue wiggling until I get it to turn on without ticking, if I get it to turn on without ticking, it will fire and run for about 15minutes. Then dies and am back to wiggling... Now. with the key on, if it ticks, the when I hit the brakes, The dash lights come on, and the fuel guage goes whacky and the Rear Defroster toggle switch light comes on. I unplug the ecu and I get the same thing... But no ticking from the Relay...

goldenjeep17 · 02-11-2010, 08:22 PM

Sounds like you have some serious gremlins... intermittent connection problems are the worst to troubleshoot and fix. Good luck!

talentjeep · 02-11-2010, 08:34 PM

wow.

so when you say "ECU" you mean the yellow box labeled "AMC" at the base of your steering column under the dash.

you're saying that it runs when you unplug that?

klock89 · 02-11-2010, 09:05 PM

Okay let me re-explain.

Wife was driving and AC pump had no freeon, she adjusted the heater, to the AC position, and Switched the roll bar from high to low(thought she rolled it to off). AC Pump seized, Snapped Belt.

Yanked the AC Pump. Connected the Inlet to the pump and the Outlet from the pump together with a Copper Plumbing Male to Male coupling and some Teflon Tape. Took the Fusible linked wire and completed the circuit by connecting it to the battery. Went and got a smaller belt, tossed it on, Ran good for about a day or two.

Then Started acting as if its not getting any gas. Though it has plenty of Gas. You can smell the excess strong. Changed the Fuel Filter, and Pump anyways.
There is a ticking under the dash... It comes from a relay under the dash, and its not a low ticking, and has never ticked before, but this is a LOUD tick.It only ticks when you turn the key on(Same time as the fuel pump kicks in) Relay is....

I can get it to fire up,but takes some wiggling of the ECU Wire Harness going through the fire wall.

My Fuel Guage is also going HayWire. And Like I said I can smell it releasing a major excess of fuel,but not when it fires correctly. When I turn the key to the on position, the ticking kicks in,and the fuel gauges goes all way to the lower right hand corner(nearly a full tank past full)

I can also remove the gauges fuse, and they still power....

I have traced out any possibility of a bad ground at the engine or anything to do with the fuel pump as the problem started before I changed it...

Therefore, NO It will not fire without the ECU being plugged in... It Has to be plugged in and the wires must be wiggled in order in order to get it ton run, and it takes about 45 minutes of wiggling to get it to run.

ajamison · 02-11-2010, 09:07 PM

i had a similar problem with my old YJ, after fighting with it for a month or so, i just replaced the whole wire harness

klock89 · 02-12-2010, 12:09 AM

what harness? The ECU Harness? And any other thoughts?