Power FC Strange Timing Drop at Idle
02-22-09, 05:56 PM
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Strange Timing Drop at Idle
I have been fighting with probken for months and can't find anything in the forum. Basically, when the car starts it idles fine until it gets up to +80C, then, sometimes, the idle will hunt until I give it a good run.
When I check the logs everything is fine expect the timing for some reason logs on the commander as IGL +4 and IGT -6, the map cells are set at IGT +36, IGT +26. When I increase the timing on the commander the car idles as it should. I can't understand why the PFC will cut 32deg. of timing. THe knock is zero, the IGN adjustments for temp, boost, etc are all set at 1.0 and it still does this. ANy ideas?
When I check the logs everything is fine expect the timing for some reason logs on the commander as IGL +4 and IGT -6, the map cells are set at IGT +36, IGT +26. When I increase the timing on the commander the car idles as it should. I can't understand why the PFC will cut 32deg. of timing. THe knock is zero, the IGN adjustments for temp, boost, etc are all set at 1.0 and it still does this. ANy ideas?
02-22-09, 06:46 PM
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In my searching I found an answer:
"Have you noticed that the actual timing at idle does not match the maps.
You have to use the DATALOGIT and change your three idle speeds to 0 inorder to enter timing that the PFC will really use.
17 with 3 split is mine.
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THanks
"Have you noticed that the actual timing at idle does not match the maps.
You have to use the DATALOGIT and change your three idle speeds to 0 inorder to enter timing that the PFC will really use.
17 with 3 split is mine.
__________________
Best Bang For The Buck! "
THanks
02-24-09, 07:43 PM
#3
I have looked into this. With the Power FC controlling idle (idle speeds not set to 0), once the ELD comes on (including the cooling fan) it switches to a different idle feedback system. It will advance the timing from somewhere around -5 L -20 T to around 5 degrees leading, and there's really nothing you can do about it. That was with idle set at 850rpm through the PFC. The PFC will ignore your timing map in the idle area unless you have a datalogit set all the idle speeds to zero, which will deactivate the ISC feedback as well (which has its own set up of advantages and disadvantages).
If you plan to keep the PFC idle control circuit, I have found the best luck with this setup (streetported 550/1300):
Idle A.E 850
Idle E/L 850 (so that the idle speed stays the same when the fans come on)
Idle A/C 950
idle AFR can't be much leaner than 13:1 or it will surge. That means your air and water temperature correction maps have to be well tuned. Air adjust screw (between the lower TB elbow studs) must be screwed in all the way and then backed out between 1/4 to 1/2 turn. O2 feedback should be off. Try those settings and also do an idle learn procedure from the Apex'i manual.
If you plan to keep the PFC idle control circuit, I have found the best luck with this setup (streetported 550/1300):
Idle A.E 850
Idle E/L 850 (so that the idle speed stays the same when the fans come on)
Idle A/C 950
idle AFR can't be much leaner than 13:1 or it will surge. That means your air and water temperature correction maps have to be well tuned. Air adjust screw (between the lower TB elbow studs) must be screwed in all the way and then backed out between 1/4 to 1/2 turn. O2 feedback should be off. Try those settings and also do an idle learn procedure from the Apex'i manual.
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