random ignition cut out on 87 yj

[bigkw91]

Hey guys.

Im having an issue while im driving the tach will drop to zero and ignition will cut and vehicle will stall. Its not the battery or starter. Both are new

Also has new cap rotor and wires.

Checked for loose connections. Non found.

If i mess with the coil pack. Or main wire it sometimes starts right away.

Thanks for the help,
Kris

 

[69jeepcj]

I had a similar problem with my jeep last winter, it was the coil going bad. turned out it was leaking and once it got heated up the jeep would just die.

 

[bigkw91]

I had a similar problem with my jeep last winter, it was the coil going bad. turned out it was leaking and once it got heated up the jeep would just die.

Also sometimes it wont start in the morning when cold. Again with some ambition i get her to start.

did that happen to you also?

 

[69jeepcj]

Yes, it would crank a few times and was like the battery was dead and I had to jump it. It would crank slow then not at all. I have a high compression engine though and takes a lot of juice to crank it over. When I replaced the coil this problem went away. Only thing I can figure with mine was that the coil was leaking, so I figure that wasn't allowing full 12 volts through all the time. If you take off the coil wire (plug wire) and look down where it went on at, you should see a Phillips screw head down in there, that screw had loosened and allowed liquid to seep out. I cant say that the hard start is directly related to your problem but it sure seemed to be related on mine.

 

[bigkw91]

Ok. Well it wasnt the coil. So u performed tge nutter bypass. All went well and started up just fine.

Now i have one concern. With the timing. Before the bypass time was set at 16-18* advanced. I know stock is supposed to be around 6... after the bypass. I wouldnt get any throttle response unless advaced to 28*. I tried 8-12* and she was popping out the carb bad.. prob close to 12 inch flames.

Now its set around 28 drives great and no knocking that i can here and has instant throttle and start up in literally 1 crank of the starter.

What do you guys think about that.. maybe timing marks/balancer isnt on correctly?

 

[PoliceMonkey161]

At 28 degrees you have likely skipped/slipped the the timing gear and chain.

 

[69jeepcj]

^^^ I tend to agree, but it is also possible that your harmonic balancer ring slipped, if so, your timing readings will be all wrong. to check: bring the #1 cylinder to top dead center on compression stroke, then look at the balancer and see if your timing marks line up, and that your rotor in the distributor is pointing to the #1 spark plug tower on the dist cap. If the rotor lines up and the timing marks are correctly aligned then the balancer ring didn't slip, and neither did the timing chain/belt. If that is the case, I don't know why you are getting such high timing at idle.. would you agree PoliceMonkey? what are the rpms at the 28*