*Solved* RPM dip then car dies ONLY when AC on after airbox tune

[sbay]

Have an interesting issue (that’s been beaten to death but can’t really find a solution) where ONLY when I have the AC on and I’m pulling into parking spot, turning the wheel hard, or slowing down to a light while coasting in neutral, the car’s RPM dips and then I have to either blip the gas to save the car from stalling, or it stalls. Happened much after I installed my airbox and Alpha-N tuned it. I reached out to the tuner and we tried raising the idle but that didn’t get much progress. Something about the engine being under load with the AC on is driving things haywire when pulling into an idle.

Couple notes:
- I cleaned my ICV well
- Car is manual swapped with the brown clutch switch (cruise control works)
- It’s fully flashed as a manual which the tuner did to make it as “factory of a manual” as possible
- Using an MSS54 DME with just the Alpha-N tune, haven’t done the MAP conversion

Any ideas?

*Solved - see solution in thread*

[Slideways]

Check for vacuum leaks mainly around the ICV with a smoke test. Which airbox?

[sbay]

Check for vacuum leaks mainly around the ICV with a smoke test. Which airbox?

Karb Race…I did a visual all looks good but going to smoke test it and report back

[davidinnyc]

Do you have power pulleys installed?

[sbay]

Do you have power pulleys installed?

No power pulleys…all stock. Tried a new fuel pump too. It’s very sporadic (maybe 1-2x out of every 10 stops)…feels like the car is choking to a slow death. Contemplating just living with it lol

[ugaexploder]

i'm convinced this symptom is related to VO coding

[karter16]

Can anyone remember if anyone with a genuine CSL has experienced this issue? I'd check CSLregister but of course it's down at the moment…

I'm currently investigating a symptom I'm observing where turning air con on pushes lambda lean by approx 5% at idle (and bizarrely it stays lean).

The KKOS module and parameters are identical between Euro M3 and CSL program code, so I'm inclined to think that it's a behavior specific to the CSL RF/fueling calculation path rather than a VO coding issue. I'm logging a bunch of stuff at the moment to see if I can figure this out.


Sent from my iPhone using Tapatalk

[davidinnyc]

I’m running a clean CSL DME and sometimes when I slow down at a stop light and the car shifts down from 2nd into 1st it hits ~500 RPMs, bounces, then shifts down to 1st and then dies when it hits 500 RPMs again… it’s happened maybe 3 times in the last two months or so.

[Slideways]

Can anyone remember if anyone with a genuine CSL has experienced this issue? I'd check CSLregister but of course it's down at the moment…

I'm currently investigating a symptom I'm observing where turning air con on pushes lambda lean by approx 5% at idle (and bizarrely it stays lean).

The KKOS module and parameters are identical between Euro M3 and CSL program code, so I'm inclined to think that it's a behavior specific to the CSL RF/fueling calculation path rather than a VO coding issue. I'm logging a bunch of stuff at the moment to see if I can figure this out.


Sent from my iPhone using Tapatalk

At 2:22 -

m3dragon's complete CSL conversion

[karter16]

At 2:22 -

m3dragon's complete CSL conversion

Awesome thanks for this - very helpful information


Sent from my iPhone using Tapatalk

[sbay]

At 2:22 -

m3dragon's complete CSL conversion

Interesting, that’s about exactly how mine behaves as well. It’ll go down to about 500-600 then either recover or stall (AC on)

[Slideways]

Awesome thanks for this - very helpful information


Sent from my iPhone using Tapatalk

Yeah, would this have anything to do with the compressor clutch engaging? In the video, it only happens after he goes full throttle. I believe Obioban said that the AC compressor disengages at high RPM or full throttle, so it really is not necessary to turn it off to maintain full power.

[BL92]

really can not diagnose a problem with out logging in Testo

Vacuum, AFR's, Fuel Pressure always a go to

There will be a setting in the map, that needs to be looked at when AC is on

either it bumps idle speed or voltage or changes to ICV etc

now that VE has changed with Airbox etc, it's causing an issue

[karter16]

Have an interesting issue (that’s been beaten to death but can’t really find a solution) where ONLY when I have the AC on and I’m pulling into parking spot, turning the wheel hard, or slowing down to a light while coasting in neutral, the car’s RPM dips and then I have to either blip the gas to save the car from stalling, or it stalls. Happened much after I installed my airbox and Alpha-N tuned it. I reached out to the tuner and we tried raising the idle but that didn’t get much progress. Something about the engine being under load with the AC on is driving things haywire when pulling into an idle.

Couple notes:
- I cleaned my ICV well
- Car is manual swapped with the brown clutch switch (cruise control works)
- It’s fully flashed as a manual which the tuner did to make it as “factory of a manual” as possible
- Using an MSS54 DME with just the Alpha-N tune, haven’t done the MAP conversion

Any ideas?

By chance are you using Terra's modified 0401 binary to work with the standard M3 32300 bootloader?

[Slideways]

By chance are you using Terra's modified 0401 binary to work with the standard M3 32300 bootloader?

Can he use that with a non-HP?