CoffeeCommando

Has anyone retrograded their ignition system with the coil packs back to the distributor setup? If so, what was required?

I'm pretty sure I'm getting misfires due to the coil packs on cylinders 3, 4 and now 1. My vac gauge has indicated "improper ignition timing (14-16 inches of vacuum) for a while now. I have no intention of putting the same thing back on there as there is only dealer/junk yard support for that amalgamation.

I'm going to start hunting for junk yard distributors and ECU's from 98 and 99 models along with the wiring harness.

I imagine I need to check the ECU wire pin-outs to make sure they all match up. Does anyone have a reference or know where I could find detail model year specifics for something like that?

lazyxj

Several on Naxja have switched to a remote coil pack that uses spark plug wires. This is one of the earlier threads and should answer your questions.
http://www.naxja.org/forum/showthrea...er+coil&page=5
The coil pack comes from a V10 Viper.
The Viper uses two coil packs, a 6-cylinder and a 4-cylinder.

The coil pack used on the 99-01 XJs is a pain to deal with when getting to spark plugs. Jeep provided little slack wire and you can't get coil out of the way.
To make it a little easier on my 2001, the coil's wires were cut and extended by 15", enough to pull the coil rail out of the way without unplugging it

CoffeeCommando

That's a good slice of info. I'll keep that in mind.

I've been doing some thinking and checking prices and decided I'll get the ignition coil from RockAuto since they're only $55 a pop.

I've tested mine and I keep getting no measured resistance between any of the pins and the actual coil extensions in the spark boots. ?? Between some of the pins I get 2-5 ohms. I think it's time for a replace. The FSM says it should be between .75 and .88 ohms between the primary and I'm guessing ground.


I'm investigating this because of misfires with accel and decel. I swapped the cam sync sensor with another one I had that looked to be a bit better quality and fitment and it cleared up until the operating temperature was reached, then it became intermittent.

One thing I've noticed is that when the misfires are happening my fuel trims go completely flat (all 0's). Then when the misfires stop the fuel trims are operating and the AFR is out of the lean condition. I'm not sure if misfires are causing lean, or if lean is causing misfire. I have no idea how to diagnose separating those two from each other so I'm just going to get the coil for the time being since it probably should be replaced regardless. The FSM says to replace them every 60K miles.

lazyxj

The coil rails should last more than 60,000 miles, my 01 has three times that and still works fine.
I see no change interval listed in the FSM, other than changing plugs every 30,000 miles.
There shouldn't be measurable resistance between the coil rail's plug pins and the spring wire, in the spark plug boots, the plug's voltage is induced into the coil's secondary winding.
The coil is a transformer.
Are you sure the cam synchronizer is correctly installed and adjusted, according to the FSM?
Even being off a bit can cause all sorts of drivability problems, including misfires.

The trim levels should never go flat when the engine is running unless there is an electrical short or intermittent bad connection, it sounds like the O2 sensors are losing their connection to the PCM or possibly the PCM is losing power and momentarily shutting off the ignition and/or injectors.
Time for some more investigation.