Hello all, and happy new year. Since installing my EMU Black into my car, I’ve been chasing a misfire with my car and I could use some help finding the cause. The engine is an Audi 2.2L 10VT that is triggered off a self-made crank mounted 60-2 trigger wheel and using the factory hall sensor for cam position. The engine starts and runs fine until around ~3300 RPM where I essentially become “misfire limited” in RPM where ignition breaks up. I initially noticed that during the misfires my cam trigger tooth was erradic, so I set the disable cam sync to 2800 to try to better isolate the issue, however this moved moved my misfire to 2800 (matching the disable value). Bumping the disable value back up to 20000rpm moved the misfire range back to ~3300 RPM or so.
I’m really scratching my head on this. Before the problem area, the car runs well and I’ve been able to road tune it to 7psi. It’s pretty happy until hitting the 3000 RPM range, then it just falls apart. It doesn’t matter if it’s under boost or vacuum (it will do the same thing on the highway under light load). Any suggestions are greatly appreciated.
So I’ve tried:
Replacing all ignition coils (currently running “red top” VAG coils)
Inspecting all wiring
Replacing Cam/ hall wiring with shielded wire (no change)
Reducing ignition timing in the affected area (no change)
Trying to disable CAM SYNC at various RPMs
The scenario for misfire can be seen below at about the 9 minute mark (I was messing with settings before that).
20250101_1428.emublog (538.1 KB)
4KQ 10V.emub (146.9 KB)
Thanks ECUMASTERS!
Why is your Primary Trigger type set to Multitooth? You should use Toothed wheel with 2 missing teeth.
Thanks for this question. To be honest, I think I selected this because I didn’t dig deep enough into the software to realize there was a difference between multitooth with two missing teeth and toothed wheel with 2 missing teeth. I’ll correct this immediately. Is there an alternative strategy utilized between the two trigger wheel types?
So I made the trigger tooth change and played around. The car had no interest in starting after making the trigger wheel change, so I reverted back, started the car, then switched it again. This seems to have raised the misfire area to ~4000RPM, however it seems like I need to adjust the base timing again, as the engine will not restart if I shut it off with the previous trigger angle I used in the “multitooth” setting. I’m hopefully optimistic I’m on the correct path. If anyone else, has any suggestions (or challenges my previous settings), I’m certainly welcome to the discussion!
20250101-Trigger wheel with two teeth missing.emublog (261.1 KB)
You are not on the right path using multitooth. Use toothed wheel with 2 missing tooth and adjust your trigger settings properly using strobe lamp.
2nd’ing what Dabrowsky is saying
If you look at your logs they are full of trigger errors and misfires when the engine is running, particularly after coming down from 3-4k rpm
If you have a 60-2 wheel installed change the settings to ‘toothed wheel with 2 missing teeth’ and retime with a timing light
Multitooth it’s relying on the cam signal for synchronization. toothed wheel with missing teeth it now knows the crank position without cam position signal, and when it has it, it can know engine phase as well.
The ‘ignition cut’ is occurring because its losing reference on the crank position essentially and misfiring
Thanks for the help. I went ahead and made the change. With secondary trigger disabled, it runs much better. I now have an issue where it won’t run when the secondary trigger is enabled. As my secondary trigger is a hall sensor run off the distributor, I’m wondering if the position is slightly off causing a trigger error.
more likely it’s 180 out in my opinion.
can you post a scope log?
Hmmm, it appears they don’t let you upload emublack scope files, unless it’s V3 (which I am not)…
I’ve definitely uploaded and downloaded black v2 scope logs before… so that would be news.
google drive link also works, just be sure to set permissions
So I took enough apart to see the cam gear. Thanks for the help all. Sure enough, it was about 180 off. I ended up having to move the ignition offset to 5 which didn’t seem to make any sense (as it’s a 5 cyl) which effectively is back on cyl 1, but it’s running (better) and starting consistently.
As I have a cam sensor wired up (but not used now) what can I gain from using it?
Allowing the engine to know what phase it’s on allows for true sequential ignition and injection.
I have done tests where without the cam sync the ECU is kind of guessing what phase its on, so sometimes it starts right up and other times its 180 out. power cycle, roll the dice and hope its correct this time as its a 50/50 chance.
Engines (i know this for i6’s) usually stop in one of 3 positions. Can’t say for certain with that 5 cylinder if that’s also the case but I’d reconnect the cam sensor and try and get that working.
The Ecumaster trigger settings are a bit of a curve ball from the normal Link/Haltech way of thinking but once you get your mind wrapped around it, it does make sense.
Ignition offset of 5 does make sense for 180 out (cam mind you, so 1/2 speed of crank), that puts the ignition event on the opposite phase of the 4 stroke cycle, or 360* different, or 1 crankshaft revolution.
This is exactly my situation- cam was 180 out. If I add the cam sensor back into the equation, will this affect the timing strategy used by the ecu?
I would expect it could. best to add it and check it again with a timing light.
Thanks all for the help. I retimed everything last night with the 60-2 trigger wheel and cam sensor and it starts a lot easier. No misfires, trigger errors or deviations in trigger tooth anymore and I now have the whole rev range to work with!
3 Likes