Knocking after changing Spark signal generator.

[George2]

So the 91 got me home again, and then wouldn't start next day.

Troubleshooting found no spark. Opened distributor, and found spark generator module in the bottom of the generator chewed to junk.

Changed the module, and put the distributor back in, and with a little tweaking while locking down the collar lock, got Jeep to start and idle. Thankfully, there's no real need to rotate dizzy like other vehicles, to get timing on the spot.

My problem is when driving under load... the engine knocks like a monster. i know the advance/retard is all controlled by the PCM, but I'm wondering what i missed- it starts and idles wonderfully. It's just under load that it knocks.

Any ideas? Anyone have this happen, and solve the issue? I'm afraid it's going to be something stupid. With me, it typically IS something stupid.

Thanks!

 

[joe_peters]

1. In the distributor is a synch sensor--it feeds data to the PCM for fuel injector firing pulse.

2. In the bellhousing, upper left, is the speed sensor aka crank sensor (CPS/CKP)--it feeds a signal to the PCM for the ignition.

3. No knock sensor on the 91+ HOs.

4. I would try moving the distributor a tooth or two, as that is the only thing you changed. Try moving it one or two CCW, if that doesn't help try one or two CW.

 

[George2]

I'll give that a try- Thanks!

 

[Matthew Currie]

If you had to tweak it to start, and it now runs up to speed but knocks, I'm guessing it's one tooth advanced.