I'm new to the Wrangler but an older wrench turning Mopar guy. I bought a 93 Wrangler 4.0/5spd with 185k and have been correcting minor issues from less than adequate repairs from the PO. Overall my Wrangler is in very decent shape for its age.
I noticed that the coil was zip tied to the motor mount. Upon further inspection I noticed the distributor cap was not not seated correctly and that the wiring harness was spliced on the distributor side both at the connecter end and on the inside. I found that the mounting hole on the distributor for the cap screw was stripped. I tapped the screw lightly and the cap seated. This was a temporary fix. I could not find where the coil mounted so I drilled two holes on the jack mount and bolted it there.
I found a NOS distributor on ebay (military surplus) for a 94-95 and after some research on this forum found that it would work in my 93 without modification. The only difference that I saw was that the new distributor had a different Hall's effect...the connector was the same.
I replaced the distributor (it came complete with cap and rotor). The Wrangler started and idled fine but when I went out on a test drive...it pinged like crazy...as if the timing was off. The distributor has a key way that only allows the distributor to mount 180 degrees so I knew it was installed correctly and not off a tooth. After researching the forum, I found that the 93 timing is controlled by the ecm. The distributor itself has a U shaped tab that does not allow any turning of the distributor once the holding bolt is in.
I started looking at other possible reasons for the pinging and lack of power. I found that there were two vacuum line that were dry rotted and/or cracked. One was the line to the fuel pressure regulater and the other one was near the firewall near the battery (but not the map sensor). I disconnected the battery to reset the ecm and then took Wrangler out for a test drive. Wow, the power was amazing...so much so that my test run ended up being 50 miles (I was elated...). I stopped for ice cream and upon getting back on the road...the pinging returned!
I pulled over and checked the vacuum lines again and they were fine. Started the Wrangler and the pinging was still there with light throttle. I disconnected the battery to reset the ecm and the pinging was still there. At this point I'm scratching my head...because those were the only things I had done to fix the issue. So I decided to drive home with this apparent lack of timing. I started it up and the pinging was gone...ran strong all the way home. My Dad always said..if you didnt fix it..its still broke...even if it seems to have fixed itself.
Since then...the pinging will come and go. I can tell as soon as it fires up and I give it light throttle. When it does this...I shut it off and restart until it starts and have no ping. Sometimes it takes 4 or 5 restarts but once it starts with no ping...I can drive it 100s of miles with no issue. I'm puzzled...is it the ecm...is it a bad fuel pump...is it a bad coil...is it some sensor sending bad info to the ecm (no codes).
Help! I dont want to start throwing parts at it...that is costly. Sorry for the long post...
Sent from AutoGuide.com Free App