help!! motor quits

It could very well be the module. Went throuigh the same thing myself.

Crank Position Sensor would be located where?

Don't have fuel injection, the 4.2 is carbureted. But thanks

Sounds like the ignition slider is coming loose. Cutting out is the ignition box usually

I would be suspecting the ignition module. They can act like that. Heat them up and they can quit. Taking the power away can reset them.

Mike

happy jeeper wrote:

thanks mike I replaced the module and all seems fine so far. 2nd time in 7 years. Tell me they last longer than that.

Motocraft ones last usually, Wells ones are iffy right out of the box.

A shaky ground to the body tub can also cause the module to 'fail'.

Mike

happy jeeper wrote:

That is weird, my module is mounted on my Fiberglass fender, by a previous owner who put the new body on. I ran the Jeep for about 8 months until the wires rotted off the old module leaving me in the center lane of the freeway, thankfully the traffic was light enuff I had enough momentum and space to get to the shoulder. Replaced it with a module from NAPA with a 1 year warranty for US$35. Then ran about 4 months until the new one got flakey, leaving me stranded twice. Jeep would run fine for about 100yds than start coughing and misfiring. Replaced that one with a free replacement from NAPA. When I took the "Bad" module in they tested it multiple times, and it tested fine and since I already installed the new one the counter guy said "oh well they don't retest them after they are returned so we will just say it failed". But that is the only thing I changed on my Jeep and it has ran fine since.

I am not sure how long the original one was on there, looked pretty old. I have heard quite a few times that they need to be grounded but mine isn't. My plan is to move mine in the cab to remove it from the heat, which I have been told is what kills them.

AMC can mean 'All Makes Covered' and yes, that mesh wire from the head to the firewall exists on the CJ's.

Mine has a Ford starter setup with a GM ignition key.

Mike

Lee Ayrt>

You can run into ground loop issues with a glass body. Basically the ignition module is stealing a ground through the distributor rather than the direct ground on the metal body.

If some other part gets shaky, all kinds of strange symptoms can happen when each part doesn't have a dedicated ground.

I would recommend a dedicated ground to the module to avoid troubles.

Mike

aGraham wrote:

Why don't you add one? Won't hurt anything, and it's better to have one too many ground straps than one too few. At minimum, you should have a strap from frame to engine and frame to tub.

Robert Bills KG6LMV Orange County CA

I will, but there's a bit of context that I didn't include in my original post. Right now the tub is sitting in my driveway, the frame is next to it and the engine is on a stand inside the garage.

I'm pretending to be all the king's horses and all the king's men, putting Humpty-CJ back together again, and I was fishing Mike's brain to see where that last strap should be attached.

Yep, with a GM alternator and a Ford distributor, and a tranny shared with a couple of other truck lines. All this gives rise to a parts counter game of "Who was low bidder for parts the week my Jeep was built? What? Studebaker?"

Thanks for the tip.

Lee