Test advance strange issue

[Wolf_Tm250]

Hi,
something weird happens on an M400 I'm tuning.
During CRIP testing, i put 15° BTDC on the idle cell and all the adiacent ones, so that Ignition Advance dBTDC was at 15° and Ignition Trims at Zero (Engine Temp at 80°, etc... no corrections)
Then i pointed the crank pulley with a timing light and confirmed it was at 15°, that is to say the CRIP is correct.
The weird thing is that as I open the Test Advance page at Ignition/Crank Index Position, with Test Advance = 15°, the lambda get leaner (better combustion) and i get 20° with the timing light!
What's happening?!
Thanks

[stevieturbo]

During Crip test, does it not lock cylinder 1 to the test value, regardless of any other parameters elsewhere ?

[Wolf_Tm250]

During Crip test, does it not lock cylinder 1 to the test value, regardless of any other parameters elsewhere ?

Hi Steve,
Yes, exactly...
In fact what I can't understand is why I have 5 degrees of difference between test advance = 15 and a 15 degrees idle cell (no compensations)...

[David Ferguson]

We have to believe you that all compensations are 0. What about main trim? If you post the config, I'm sure someone will spot the flaw. If you're worried about some propriety map, just make a copy and zero that out before posting.

[Wolf_Tm250]

We have to believe you that all compensations are 0. What about main trim? If you post the config, I'm sure someone will spot the flaw. If you're worried about some propriety map, just make a copy and zero that out before posting.

MY FAULT.
All the compensations in the Ignition menu' were Zero, the Ignition Trim Channel displayed Zero... BUT I found some degrees compensation in Idle Ign Comp... very strange Trims' Channel was at Zero!

[Wolf_Tm250]

We have to believe you that all compensations are 0. What about main trim? If you post the config, I'm sure someone will spot the flaw. If you're worried about some propriety map, just make a copy and zero that out before posting.

MY FAULT.
All the compensations in the Ignition menu' were Zero, the Ignition Trim Channel displayed Zero... BUT I found some degrees compensation in Idle Ign Comp... very strange Trims' Channel was at Zero!

Not my fault. Must rectify myself.

Put all the Idle Ign Comp to Zero, but I still have a difference testing ignition values with timing light.
I discovered I have an Individual Ignition Trim cyl 1 (-7.8°) affecting the Ign Base Advance,
but problem is that ALL the individual ign trims are set to Zero!

What's happening?!
Any idea?

Thanks

[Sean]

I'm not saying this is your problem, but I have had this scenario multiple times......

1. You have the UTC connected and the ecu open for editing in ecu manager.
2. Battery voltage is low.
3. You then crank the engine and the current drain from the starter is enough to drop the voltage so the ecu shuts off momentarily.
4. This situation, in my experience, usually results in the ECU file becoming corrupted in weird ways. I have had it change all sorts of stuff totally at random.

Hope this makes sense.

[Wolf_Tm250]

I'm not saying this is your problem, but I have had this scenario multiple times......

1. You have the UTC connected and the ecu open for editing in ecu manager.
2. Battery voltage is low.
3. You then crank the engine and the current drain from the starter is enough to drop the voltage so the ecu shuts off momentarily.
4. This situation, in my experience, usually results in the ECU file becoming corrupted in weird ways. I have had it change all sorts of stuff totally at random.

Hope this makes sense.

Seems a scary option!
How did you solve in these cases? Rewrite a map from beginning?
Thanks

[Sean]

Went back to a previous known good file and started from there. You can use compare mode in ecu manager and compare a good file to your current one and see what has changed, if anything.