Jeep Strokers

Since building my motor the power has been disappointing, but fairly drivable. I have a CompCams k68-232 camshaft, and during initial installation of the distributor I ran into an issue. Following the procedure outlined in the FSM, the distributor would rotate too far clockwise past the bolt hole, causing one of the locating "teeth" to block it preventing installation of the distributor. At the time I used a distributor that had no teeth to solve this issue. Recently I have been experimenting with HPTuners and the reported spark advance values aren't quite lining up with reality. The timing advance seems to be 5-10* less than what I set in the ECU's tune. This would definitely explain a lack of power, at least in my head!

Combined with the odd issue with the distributor installation, I'm wondering if it's possible for the distributor gear on the camshaft itself to be clocked wrong in relation to the timing set? Any ideas/experience is appreciated!

I think the "issue" was in the cam castings, they all go off of a 258 cam or something. Anyway, you cut one of the tabs off the distributor hold down and you can spin it to index it. It's laid out well here and on Dino's site.

Thank you for the suggestion, I see that process now and will try it out. It's unfortunate that a cam advertised for the 4.0 is slightly off in this way.

Keep in mind that the ignition timing advance curve is locked in the ECU and that the base timing is fixed. You can either adjust the base timing by slotting the CPS bolt holes (Renix & OBD1) and "clocking" it, or use HP Tuners software to change the advance curve (OBD 2).
The distributor indexing is required in order to synchronize the injector pulse with the spark since it houses the cam position sensor. You may need to cut one of the bolt slots to index it correctly since the distributor drive gear on aftermarket cams may be ground in a slightly different position, and there'll inevitably be variations due to production tolerances.

Turning the distributor doesn't affect timing. Timing is set by the ecm. The crank sensor tells the coil when to spark with the notches in the flywheel. You turn the distributor to set fuel sync. You need a snap on scanner or a DRB from a dealer to set fuel sync.
There are several settings in HP tuners that affect timing off of the base timing table. Look at the coolant and intake temp settings. You can see how much timing is being pulled as engine coolant temp and intake air temp rises.

Cutting ears is not necessary. Remove the gear, and rotate it 180 degrees. The dizzy gear has an odd number of teeth, rotating the gear and reinstalling it gives you a half tooth of rotation.

If your problem is it always seems to be a tooth off or between 2 spark plug terminals. This will fix it.

TR1Hemi wrote: ↑April 1st, 2025, 3:25 am Cutting ears is not necessary. Remove the gear, and rotate it 180 degrees. The dizzy gear has an odd number of teeth, rotating the gear and reinstalling it gives you a half tooth of rotation.

If your problem is it always seems to be a tooth off or between 2 spark plug terminals. This will fix it.

I tried doing this on two different distributors, but when I rotate the gear 180 degrees and try to insert the pin that blocks it, it doesn't align; it seems to be slightly off center. I think if I hit it hard, the pin would fit through, but I'm afraid of breaking the gear.

Let me start by saying I don't understand that whole "180 degree rotation" thing, but you can take a flat screw driver and nudge the oil pump to get it to align with your distributor.