Won't start

[splntrp]

I've been reading around for several days but not having much luck with getting the cj to start. I have an 86 CJ7 , AMC 258 i6 / 4.2l , 4 speed with the carter BBD.
Everything was good until Friday. It had been running a little rough but I figured it was the choke and needed a tune up. After playing with the choke and getting that right now it won't start consistently. It is getting fuel but inconsistent fire.
I've bought and replaced the starter relay, ICM, and coil. Each time when it didn't work I took the new off and put the old back on.
I was able to get it started, but then when I would let it sit and come back it wouldn't start. The time it did start it was hooked to the battery charger on the 200 amp setting.
The starter turns, the rotor inside the distributor turns, checking power at the coil I get 7 something volts with the key on, when it did crank the colts went up to around 10 or so.
The last time it cranked we had put the new icm on with the charger connected and left it that way. I then started it several times with no problems. Come back a couple hours later after being on the charger and it won't do anything again.
I'm going to have the battery checked but I'm at a loss now as far as next steps. Any ideas?

 

[Lumpy Grits]

:ww:

Can you see fuel squirt down inside the carb when you work the throttle linkage full stroke?
If so, the carb has fuel. If not-find out why(fuel pump, clogged fuel filter etc)
If the ICM was one of the cheap China POS's, then I'll bet it's fried too.
Go to a NAPA and get their top of the line.
ALSO-Before you do the new ICM install. Disco the POS(+)side of the battery.
200amp is for emergency start ONLY-NOT for charging.
LG

 

[Torxhead]

You could check for a high battery drain by removing the positive battery terminal clamp and touching against the positive post to check for a spark which would indicate a short somewhere. There should be a small drain due to the computer which would give off a small spark. Better yet check for a high amp drain at the battery with a multi meter.

 

[splntrp]

Yes, you can see fuel squirting in the carb when you move the linkage.
I wasn't charging at 200 only using it to start. Advance checked the battery, off the vehicle, and said it was good.
ICM was cheap, only one O'Reilly had.

 

[Lumpy Grits]

ICM was cheap, only one O'Reilly had.

Who made the ICM?
LG

 

[Torxhead]

You might have a bad connection somewhere. The slip on coil connector can be one source of a problem. The fusible links off the starter relay can go bad after 30+ years also. You might try jiggling around wires under the hood when you get it running next.

 

[splntrp]

Thanks for the ideas. I got to looking around at the wiring harness and the previous owner had done a number on it. Several splices that were loose. What was so strange was that they took time to solder the splices but then covered them with duct tape. I found several that were bad and fixed them and the cj fired up no problems. So tomorrow I'm going to go through the rest of the harness and see what what else I can see. Thanks for the help.

The brand of the new control module was masterpro from oreillys. I'll probably go to napa soon and get a better brand to have ready for next time.

Thanks again.

 

[splntrp]

You could check for a high battery drain by removing the positive battery terminal clamp and touching against the positive post to check for a spark which would indicate a short somewhere. There should be a small drain due to the computer which would give off a small spark. Better yet check for a high amp drain at the battery with a multi meter.

For next time how do you check for high amp drain at the battery with a meter? Measure voltage across post while some one cranks? And what would that tell you?

 

[Lumpy Grits]

"Duck Tape" is a very pour insulator.
LG

 

[Torxhead]

If I am not mistaken, the CJ came with what appears to be duct tape on the orange and violet wires running from the computer to the distributor. This was to protect those signal wires from outside interference inside that wiring harness. I took mine out and ran them through a separate split loom. Yes, it is a poor insulator. If you were to run the black or ground wire from the icm and run it directly to the battery negative instead of that distributor, it would make for a better connection for the icm.

 

[Torxhead]

For next time how do you check for high amp drain at the battery with a meter? Measure voltage across post while some one cranks? And what would that tell you?

This guy could answer that for you:https://www.youtube.com/watch?v=KF1gijj03_0

 

[Lumpy Grits]

That tape was heat resistant tape. Nut'n to do with RFI reduction.
That wire is the resistor wire for the coil, when the engine is in 'run' mode.
LG