Help 92yj not start just cranking. NO SPARK

marcus · #1 07-23-2008, 11:01 PM

Ok here is the story my brother has a 92 wrangler 4.0 auto and his fuse box melted thanks to years of wrong size battery and mangled wires etc.. truck ran before the swap began. I had a 93 parts truck with 4.0 auto decided to swap harness / fues block. I took my harness off the 93 and my dad took off the 92 and tried to do the swap by himself. Not all the connections were the same the 92 had a three prong for the cps and the 93 had a 2 prong so i swaped the cps. swapped the cap and rotor. the truck will crank and get power to the coil but no spark from cap to plugs. So far ahve cleaned the cps swapped the coil cap rotors I think the swapped the ecm. Whats the next step a couple of wires leading the tranny arent hooked up im sure since i have only been down there half the time. Guages and lights work brake light work fan works etc. Have swapped out some relays but where should i check for the spark issue.

JeepDawg · #2 07-23-2008, 11:40 PM

Go find another 92 wrangler and get the harness from it.

The early 90's were very dynamic years for those engines as far as the electronics whent.....in many cases things changed mid year......

LEVE · #3 07-25-2008, 09:48 AM

Jdwag, the harness remained stable from 1992 through 1993. Replacement CPS designs were not stable, hence the connector changes.Since the CPS was changed, it still could be the problem.

However, I'd be looking to see if the AutoShutDown relay was enabled. If it is enabled, the CPS is doing it's job. Then look for a problem further into the ignition circuit. If it is disabled, the fault likely lies back with the CPS.

Have there been any codes set or recovered?

marcus · #4 07-25-2008, 08:33 PM

Thanks for reading thru that mess of a post I left. How do I check if the auto shut down relay was enabled, and how do I go about recovering codes?
--Thanks

LEVE · #5 07-26-2008, 03:33 PM

Check to see if there is voltage on the positive side of the coil. The ASD, when enabled, will provide voltage to this point. This point then feeds both the ignition and fuel delivery circuits. If it's not enabled... likely the CPS is not working.

Codes can easily be checked by Going HERE ....