Jeep Wrangler Forum

Jeep Wrangler Forum (
-   YJ Tech Forum (
-   -   Lil help plz (

Buckshot1956 10-27-2013 12:37 PM

Lil help plz
My '89 YJ 4.2 was running like a dream then just died going down the road. Would not start. No spark. All other electrical systems seem fine. ???

0III0forlife 10-27-2013 12:43 PM

There is an ECM (engine control module) located at the bottom of the driver's side front inner fender well. Down under the windshield washer tank and radiator over flow bottle. This is most likely the culprit if it was running fine and just quit giving spark.

If you want to check the coil, get a jumper wire that is 12 ga atleast, and run it directly from the pos side of the battery to the coil where the pink wire hooks in. pink wire is power in, the grey wire is the signal wire to the tach. Should start then. but cant be shut off without pulling your jumper wire off.

Buckshot1956 10-27-2013 12:57 PM

Thank you very much. I'll do some testing. Between games!

Buckshot1956 10-28-2013 06:11 PM

Ok, i did the direct to coil test. Then i chemed voltage into the coil. I have a out 8.3v in. I am not getting anything out. The secondary coil checked at 8.05k ohms. Below spec of 11.3-15.3. I'm thinking bad coil. Any thoughts?

CMike357 10-29-2013 10:20 AM

I would change the coil first and if that doesn't fix the problem, troubleshoot from there. Keep us posted.

wakeboard236 10-29-2013 04:25 PM

Same sort of thing happened to me except I died at a complete stop at a red light. Would not start again and wasn't getting a spark. I ended up blowing my ECU fuse, once i replaced it, it got going again. Still not sure what caused the fuse to blow, but for the time being I'm running. It's worth a check atleast

Big Cole 10-29-2013 05:34 PM

64 Attachment(s)
Had the same issue with my 89 YJ. It would randomly die while driving down the road. Replaced the engine control module and never had the problem again.

Buckshot1956 10-30-2013 08:25 PM

Well, the problem was the control module. I put a new one in this pm & she fired right up. Thank you to all. I'm a newbie to Jeeps but did a fair amount of mechanicin in the 70' & early 80's. Now i want to work on the squeaks!

Buckshot1956 10-30-2013 08:42 PM

I would like to do away with the complex air cleaner assembly and just put on a simple air filter. What are the pros & cons of doing this? It always seems to smell like it is running rich.

Decoy_58 10-31-2013 08:29 AM

If you are in California I would think that you would have to keep stock breather for smog

Buckshot1956 10-31-2013 06:30 PM

You are probably correct but I'm in Arkansas.

Wombat Ranger 10-31-2013 10:31 PM

^^ Good answer. Arkansas is a much better place to be in my experience.

Start by doing the "Nutter" mod to bypass your stepper motor in the carb. There ade several writeups in how to do this. Google can help you find them. Once that is done, remove the 20 miles of smog hoses and all the crap associated with it. The only vacuum lines you should retain are the distributor vacuum advance, pcv, oil breather, and the 4x4 CAD actuator. Plug everything else off. Just that alone made my jeep run way better. Once all that crap is taken care of you can use whatever air cleaner you can fit on there, cuz it no longer cares about being Green.

poi dog 11-01-2013 12:44 AM

I have 95 YJ with a 4.0 HO and live in CA have a K&N system engine runs great

poi dog 11-01-2013 12:46 AM


Originally Posted by poi dog (Post 5806578)
I have 95 YJ with a 4.0 HO and live in CA have a K&N system engine runs great

NEVER fry bacon naked

western196611 11-01-2013 06:00 AM


Originally Posted by poi dog (Post 5806594)
never fry bacon naked


Buckshot1956 11-01-2013 05:48 PM

Thank you for the lead WR. I'm up in the NW corner and lookin to take a ride through the Ozarks this weekend. Fall foliage is on fire!

Wombat Ranger 11-02-2013 11:46 AM

Not a problem!

I was stationed at Barksdale AFB in Shreveport LA and I had friends I visited up in the Marshall area. It was really nice up there, that was some of the best times I have ever had out there

All times are GMT -5. The time now is 06:51 PM.

User Alert System provided by Advanced User Tagging v3.1.0 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.