Problem with my 89 carbureted YJ

[Sting67Ray]

Hi, I have a '89 YJ that I have had for 10 years that has a problem that I cant figure out, after driving for about 10 mins it starts surging and finally dies. I was thinking originally it is a carb problem, and replaced the carb with a new motorcraft. The problem is still there, next I replaced the fuel sending unit, still no love, lastly I went thru the ignition and put in new wires, plugs, coil, etc.....still no love, anyone have anything else to try? Jeep is a 4.2 Auto.

Thanks,
Tom M

 

[Chief Hof]

Evening...fuel sending unit? Do you mean the fuel pump? Try changing that, then the fuel filter. If that's GTG consider your vacuum system.

 

[Sting67Ray]

Thanks for the reply, I will try to but a gauge on the fuel line to see if the pump is working.

 

[Sunsport]

I feel like I read people had similar issues before with a bad ECM - capacitors failed internally. It is potted, which makes it a pain, but repairable with some patience. Or swap it out.

 

[Sting67Ray]

I will check that out, I had to replace the one in my first '89, but that was about 1999, and I dont remember the symptoms

 

[Chief Hof]

The '89 with the 4.2 has an ECM?

 

[Sting67Ray]

no, I guess that was an Ignition control module

 

[Sunsport]

The '89 with the 4.2 has an ECM?

Yup, ECM and an ICM too.

 

[dodgerammit]

I believe it's referred to by AMC as the CEC system. Uses a couple of temp sensors, an O2 sensor, a basic computer and some metering rods in the carb to adjust fuel air mix. The late CJs, the carbureted YJs, and AMC Eagles with the 258 had it.

 

[Chief Hof]

Learn something new every day...thanks Gents!