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Hello, I've got a supercharged 2ZZ managed by an EMU Black. The tune was done for me and the car makes good power and is generally running very well with the exception of low speed revs and idle.
Some symptoms I've experienced are:
- Revs hanging after blipping the throttle
- Revs dropping too low causing the car to oscillate a bit or in some extreme cases (cold car) stalling the car
- Sometimes the car settles at an idle that's simply too high, almost as if the TB has got stuck. A quick/gentle blip of the throttle normally brings it back in line.
- Checking the log shows that the various correction mechanisms are maxing out to try to achieve target idle.
After doing my research I hope to wipe the slate clean with the idle stuff on the ECU and tune it from scratch. The regular VE/Ignition tables I won't touch but I'll play with the idle control/correction stuff to try and get the result I'm looking for.
I'm hoping to get a sanity check on my approach, to make sure I'm not doing something silly or missing a key feature of the ECU. I'd appreciate some input.
1- Set Idle target to be 950 (warm) gradually coming down from around 1400 at cold start
2- Clear out the tables for Idle Ign Correction, DC error correction and the DC VE correction
3- Disable PID and Ignition control
I think that should make the idle pretty "vanilla" with no external influence. From there I'll start the car up and I'll tweak the Idle Ref Table to try and bring the idle as close to target as possible without any correction.
Once I've done that through the whole CLT range from cold start to operating temp, I'll reintroduce the Idle Ign Correction and DC Error correction. What I'm not sure about is the DC VE correction table and how it should correlate with the others. The way the map is currently configured as the entire DC VE correction table correcting negatively, removing a range of 5% to 3.5% VE, I think this may be contributing to the stalling but I'm not sure.
I appreciate any feedback on my approach, I'm quite enjoying learning my way through this and it would save me a day out and long drive back to the tuner to get this resolved.
you are on the right track I would be targeting cold idle around 1200 rather than 1400 but other than that you have a great approach to solving the issue