1989 yj start problems

I have an 89 yj 6 cyl 4.2 that was running fine and now it won’t start...I did plugs changed fuel filter mechanical fuel pump and it cranks but won’t start...

 

do you have spark at several plugs?
have 12v at coil KOEO (Key On Eng Off) ?

Duh but gotta ask - got gas?

Spray some carb cleaned into carb as someone tries to start - does it hit, fire and try to start on spray?

 

Those older engines can have issues like a distributor pick up coil going bad or even the ignition control module. They usually have warning signs that they are about to go though. The 258 did have a poor electrical connection that came right from the factory, This would be the slip on coil connector if your vehicle did come with one. Hopefully you have verified you are getting gas to the carb, so it must be somewhere in the electrical system. There are a couple of fusible links that could have shorted out while working on it, they are connected to the starter relay, they both have red wires coming from them.

 

Sometimes the carbon will build up on the piston sleeve and cause diarrhea that sticks to 3rd gear. Be sure take the oil cap off and put some mountin dew in. It helps get the oil flowing. And some baking soda and skittles in the radiator. I'm speaking from personal experience and I fix people's vehicles for a living. I know what I am talking about.

 

I have done lots of electrical work on mine and the only thing left is the computer and it is behind the glove box I will let you know soon .