Boxer timing problem

Man I have not worded on a diz in 100 years. In my experience the aftermarket kits either did not work or did not work for very long. Robustness was lacking. IMO until you are ready to go distributorless and make a real conversion I would just go back to factory stock. It will run as intended and then you will know the aftermarket unit is just plain bad and spend alot less time putting lipstick on a pig. If the problem occurs in the factory set-up then your diagnosis is also done and you can start looking at all the common culprits which eventually banished the diz into obscurity.

 

Does this mean that everything else is stock and the ONLY change is that the Aussie ICE unit replaces the Dinoplex unit -- i.e., you are still using the 12-point "star" trigger wheel and the stock pickup on the dist housing, and the advance is still handled by the mechanical system inside of the distributor?

Your symptom (the spark seeming to "change" posts depending on the RPM/advance) is indicative of the relationship between the cap and the rotor, when the firing event occurs, being out of whack (and it's a miracle it works on your model anyway with only 30 deg between posts ). Perhaps your new ICE unit has a different sensitivity and is firing when the 12-point star wheel is in a different position relative to the pick-up (i.e., it needs to be a different physical arrangement than that shown in the OM figure) -- but please describe the whole system more fully as that may not apply.

 

I concur on reinstalling the original equipment, then you can verify that everything is correct. If it's all good at that point and running perfectly you can try to reinstall your aftermarket carefully so see if there were any glitches in that new system. It could just be a bad unit, or doesn't work well with your vehicle. With that kind of spark jumping an inch, if there is too much resistance in one spark plug wire or a few somewhere, then the spark would tend to jump to the less resistence route. That would put you to checking all the plugs and wires for consistency.

 

It definitely can IF the relationship between rotor and cap is not right WHEN the spark occurs (i.e., with the rotor rigidly mounted to the shaft, its postion relative to the cap changes with advance). The setup in the OM figure (rotor end pointing at mark on rim and hole in the "star" wheel aligned with the hole in upper plate) is based on how the stock Dinoplex ECU works in conjunction with the pickup. No gaurantee that your new unit works the same -- i.e., IMO, it wouldn't hurt to try moving the "star" wheel a few degrees in either direction and see if this changes at what RPM the switchover occurs or if you can eliminate it.

A second point is that with the increased spark, you can get enouigh crosstalk in the (longer) spark plug wires to falsely trigger the timing light. On my TR, if I leave the wires in their stock looms (parallel and close together) and try to measure either #1 or #12, I get false flashes at the timing light. I have to remove the #1 or #12 spark plug wire from the loom holders (and let it droop down) so it's physically further away from it's neighbors to eliminate the false flashes -- just a thought...

 

Are you sure that the exchange modul has the same trigger behaviour, e.g. fires on either a rising or falling level from the distributors pickup as the previous one. An inverted trigger input would lead to pretty much the symptoms you describe.

Ice ignition seems to offer both variants (rising and falling) for their 6 and 7 AMP ignition product, maybe you got the wrong one as replacement?

 

Most 365bb's have two distributor pick-ups; one which is used and the other is a spare. If you trigger your spark box off the spare unit, you'll end up in exactly the position you're in...The correct pick-up unit is the furthest one CW, when viewed from the rear.

David

 

See pages 68-69 in your 365BB OM -- Figure 42 on page 69 shows the stock relationships of (narrow) rotor end-to-housing mark and "star" hole-to-upper flange hole that need to occur together when the engine is at the cyl #1 idle firing location:
Image Unavailable, Please Login

 

If only the Ice Box was changed, then the difference could be falling/rising trigger signal type, spark voltage, spark energy and a possible wrong wiring on reinstallation.

The Ice box is a dwell controlled transistor ignition, so the maximum voltage at the spark plugs is below 30KV. The Crane Hi-6 (is that the one you were using?) however delivers up to 40-45KV, so sparks jumping to the wrong post is much more likely here. If you do have an issue with the rotor phasing (position to pickup relative to finger position to spark wire terminal) the Crane should have made it much worse. Did it?

If you are sure you haven't touched anything else then i tend to still cling to my inverted trigger signal type theory for now.

Some random thoughts
- Make sure that the distributor cap's inside is clean and shows no cracks or fissures
- Try another timing light to be sure of the results you see
- Cross firing can be easily shown with a engine tester (Pico, Sun, Bosch) or a four channel scope with inductive pickups for the spark wires. Any modern workshop would have one, should not take longer than one hour to do this test. Clamp three or four pickups to the spark wires according to the firing sequence and you'll see what happens in an instant.

 

No, it's purpose (if you had one ) is to (more easily) set/confirm the star wheel's postion relative to pick-up when the narrow rotor end of the rotor is aligned with the mark on the rim. In the OM figure, when the narrow rotor end is pointing at the mark (and the reference holes are lined up), one tooth of the star wheel is shown as being slightly (4 deg) past the detector feature in the pickup. In your photo, it looks like the tooth on the star wheel closest to the pickup is positioned a little before the detector feature (but I can't really see the true detector feature in the pickup in the photo so can't be sure).

My advice would be to try to replicate the star wheel -to- detector feature relationship shown in the OM figure as a starting point; however, (since you are using a non-stock igniton ECU) if that doesn't seem to work, then experiment with slightly changing the star wheel -to- detector feature relationship to see if it helps or hurts (in order to figure out where it should be for your system).

 

Good point Steve, modifying the rotor phase as above provides a fix even for a wrong ignition trigger type (you just move the rotor some degrees forward or backward to either comply with a falling or rising trigger edge), so its a good approach.

Why the rotor phasing has changing while Scott just exchanged a defective ignition module beats me though. I'll have a look at the original ignition unit (AEC104BK) tonight and check if it triggers on a rising or falling edge, then we could compare that with the current Ice module you have.

 

The AEC104BK triggers on a rising edge, so you should probably have received a "7000E - 7 AMP Ignition Module suit rising trigger - 4 wire hook-up - EFI". You mentioned two trigger wires, according to the Ice installation manual this would point to a 'falling trigger' module.

BTW, the Ice website only refers to an ECU (EFI) or OE box for triggering (e.g. +12V square wave), a VR sensor (magnetic pickup in the distributor) as installed in the 365BB is not mentioned anywhere. Did Ice mention that their ignition is compatible with an VR sensor/magnetic pickup signal?

Do you know why your previous Ice module broke down, and after how many miles did this happen? The reason i ask is that a magnetic pickup has a rising output voltage with higher speed, so an output signal with 40-60 volts at WOT is not uncommon. If the Ice ignition only has a +12 V input stage for the trigger signal (as with an ECU or OE input), the high output voltage of the VR sensor might kill the input stage at some point.

 

Ok, if it has been retrofitted for a magnetic pickup then no worries! Would be still interesting if the trigger type (rising) is correct with your current unit.

Is the distributors pickup module properly mounted to the distributor body, any chance the position got changed when you exchanged the ignition module? I remember that there is only one position but might be worth a check.

 

Scott, can you check if the pickup you are using is properly mounted to the distributor body and does not shift/move?
What happens to the timing if you wire the Ice ignition to the other pickup? Any change?
Do you have an update from the Ice guys regarding your ignition model type?

After you changed the bad module against the new one, did you notice that the idle RPM was higher than before? If you have a static advance of >30º at the crank your idle speed would rise at least by 100 RPM.
Also starting an engine with about >30º static advance is more difficult, the engine would kick back a bit before properly starting (especially if you still have the original starter and not a newer replacement type), did you notice such a behaviour?
It sounds like to me that you can measure the different timing with a timing light but the engines behaviour didnt really change, or at least not that much, is that correct?

My recommendation would be to do a test run with a motor tester/ignition scope as next step to proof or rule out the cross firing as the issue, this also gives some insight why the engine is not running on all cylinders below 3000 RPM.