Ignition Question on AEM

[suprakid24]

I was searching around through logs to see what would be making my tach stumble around at 3000 and saw places where my ignition timing was at -17. I still don't know what would be making my tach bounce around at 3000 or if it is even in the tune, but I would like to know if this -17 is normal..

Thanks

 

[Turbo Drifter]

I will look at my old logs tonight, I do not recall seeing anything like that though.

Jeremy

 

[empera]

actually mine does the same thing! right under 3k...i'll take a look at my logs and see if i have the same on my ign. timing

 

[suprakid24]

actually mine does the same thing! right under 3k...i'll take a look at my logs and see if i have the same on my ign. timing

your tach stumbles too around 3k? mine has been doing it for a while, and I think I have read somewhere that it may be the TPS, but it may be in the tune also idk. But I saw those ign drops and was wondering if that was normal

 

[empera]

nah doesnt do it at idle...i suspect its when i hit start hitting boost.

 

[mk3ukr]

Guys, search AEM forum, mk3 section for this subject. There were few posts regarding this problem about 2 years ago. This 3000rpm misfire is common for many 7M. So far best suggestion was to keep ignition timing lower then 30deg. in cruising area. I saw one person suggesting reducing Coil dwell factor from 19 (base calibration) to 17.
On my car I didn't have this problem for 3 years. This year few months ago I decided to set my ignition timing and after tinkering with CPS position I got this 3-3.5K rpm misfire. It's intermittent problem, but annoying as hell.

 

[chevyeater]

Guys, search AEM forum, mk3 section for this subject. There were few posts regarding this problem about 2 years ago. This 3000rpm misfire is common for many 7M. So far best suggestion was to keep ignition timing lower then 30deg. in cruising area. I saw one person suggesting reducing Coil dwell factor from 19 (base calibration) to 17.
On my car I didn't have this problem for 3 years. This year few months ago I decided to set my ignition timing and after tinkering with CPS position I got this 3-3.5K rpm misfire. It's intermittent problem, but annoying as hell.

You've stumbled on what I believe to be the root cause of this problem. It isn't limited to the mk3 platform (Nissan KA and SR do it the worst). It has to do with the ignition synch teeth. Best fix I've found is to experiment with the CPS and synch setting until the issue is gone. The last few cars I fixed liked synch @ 0.00 (with cam sensor adjusted to match laptop and actual timing).

The OP's log though shows quite a correlation between timing and throttle angle so, I'd have a good look at the calibration first in that case.

 

[mk3ukr]

Brian, thank you for idea, I will try it

 

[empera]

the sync process is in the help files correct?

 

[chevyeater]

the sync process is in the help files correct?

IIRC it was on the instruction sheet. It doesn't cover setting a specific sync teeth value though.

 

[suprakid24]

You've stumbled on what I believe to be the root cause of this problem. It isn't limited to the mk3 platform (Nissan KA and SR do it the worst). It has to do with the ignition synch teeth. Best fix I've found is to experiment with the CPS and synch setting until the issue is gone. The last few cars I fixed liked synch @ 0.00 (with cam sensor adjusted to match laptop and actual timing).

The OP's log though shows quite a correlation between timing and throttle angle so, I'd have a good look at the calibration first in that case.

Thanks for the info, and as far as the timing dropping to -17 I think we figured it out. I have the 2 step setup for whenever I have the switch on and press the clutch (use it for power shifting at the track too). What I think it is doing is whenever I press the clutch to let out, it could still be trying to load the engine because the rpms are still up.