Need some help diagnosing my 1987 4.2 YJ

[YJ_Holse]

Hello, hoping someone could aid in some non start diagnostics.

My 87 Wrangler was my first vehicle, my late father owned it since about 95 and gave it to me when in the early 2000s. He and I worked on the thing quite a bit through the years and I learned what I could at the time so I have some surface level knowledge, mostly enough to get myself in trouble.

Fast forward in life and it ended up sitting under nasty pine trees for about 5 years. I'm in the process of revival and cannot get it running. Drained fuel and replaced with about 8 gallon non-ethenol. Had the Motorcraft 2150 rebuilt and was able to start it, for roughly two smoke and squeal filled seconds until it died. Could not replicate this afterwards. Replaced fuel pump ( it was original to Jeep ), filter, a few rubber hoses and can confirm fuel delivery to cup - did not measure PSI.

I moved to plugs and was not able to produce spark while grounded. The replacer in me decided to do the plugs, wires, cap, rotor, coil, condesor to no avail producing spark. Looked to Solenoid (firewall mounted type) has 11v off the post to coil, connector on post to coil connector is corroded. Coil connector itself (horseshoe style) has frayed wires going in, is corroded and has a small indent to where the coil posts sit. i was only able to find 12v with key on in a few select areas on the connector lead. All of this looks like it needs to be replaced?

I'm curious if I'm even on the right track, if I am to replace the wiring at the solenoid and the connector- its spliced at the loom near the firewall that goes over to ICM ( in assuming all of this is bypassed due to mc2150), can I run just a new, direct wire to avoid this splice and wire that to the two yellows going into a new horseshoe clip? I was reading there is a resistor wire (that I'm unable to locate). This is where it gets a bit unknown for me.

Sorry this is long and slightly convoluted. I've attached a photo of the horseshoe connector, loom splice and connector on solenoid for reference taken during my tune up and connector cleaning.


Thanks in advanced for reading!
Russ

 

[ytradio]

If it were me and yes I have been in the same situation, I would wire around all of the factory crap and put in a remote starter button. This way you can at least see if you can get it running. This way once it runs you can go backward through the factory wiring and start figuring out what needs to be done. My reasoning is that I personally have chased all sorts of problems only to find the problem was something completely different.

 

[YJ_Holse]

I may have also messed up the timing when I was changing the rotor- how would one distinguish between electrical issues and timing issues when related to starting?

 

[ytradio]

I may have also messed up the timing when I was changing the rotor- how would one distinguish between electrical issues and timing issues when related to starting?

Part of the reason that I would attach a remote starter button under the hood is that it makes it easier to check for fire on the ignition system. If you have a faithful companion that can help, you will not need this, but I always am working alone. Even if the timing is too far off to run it will show whether or not it is firing. Start at the plugs first, if no spark there then move to the coil. You will just have to run back the ignition system until you have spark at the plugs. If it still doesn’t run then work on checking the plug wire firing order then setting the timing. It’s possible to have everything right and the distributor be out 180 degrees. If that ends up being the case, pull it and turn it around.

 

[YJ_Holse]

I appreciate your input. Put a remote switch on the solenoid last night. I'm going through FSM wiring diagrams and cannot find a mention of a resistor wire. Any idea where this would be wired up in the chain?

Following the yellows from clip - one goes to condensor and the other to a splice, one side goes to starter solenoid and other goes to ignition switch? Unless this is spliced again somewhere for the resistor I cannot seem to locate.

Thanks again,
Russ

 

[YJ_Holse]

Found a few frayed wires, burned connectors and one yellow wire just barely connected to coil clip. I'm redoing the pictured wiring from the solenoid through the coil clip. Is the green/white wire spliced into the yellow a resistor wire? Or can I replace these with 16 gauge wire?

Thanks,
rh

 

[YJ_Holse]

If it were me and yes I have been in the same situation, I would wire around all of the factory crap and put in a remote starter button. This way you can at least see if you can get it running. This way once it runs you can go backward through the factory wiring and start figuring out what needs to be done. My reasoning is that I personally have chased all sorts of problems only to find the problem was something completely different.

Revival for update - I did all this and yes it was something different . Jeep starts now, combination of frayed electrical connectors (also had a rough time getting the replacement horseshoe style coil clip to make solid connection) and the TIMING i had knocked the distributor far more clockwise than it had originally been oriented. Moved it back and fires up. Cleaned up the carb too.

Thanks again