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Ed Blown Vert
10-14-2005, 09:35 AM
Was on the dyno checking AFR. At 4000 it was 12:1 so added 5% to the PE table @ 4000. No change in AFR. Then added another 10% then 15%. Still no change. Everywhere else I had no problem changing the AFR.

What am I missing?

Sarge
10-14-2005, 04:15 PM
In open loop.....I assume....are the O2 sensors preventing the change for some reason?

MNR-0
10-15-2005, 07:56 PM
Ed,

Monitor your "Fuel Air Multiplier" and "Air Fuel Ratio Commanded Hi Res" PIDS during a WOT run. Check what value the VCM is commanding at WOT. If it is something different to what you are commanding via your PE table then look into your program for that Open Loop AFR value.

It can only come from 5 places at WOT:

PE
PE Add vs ECT
PE Add vs IAT
OL F/A
COT

My guess it is COT, or CAT protection. Have you disabled it yet? If not, CAT protection will override the PE value.

Another thing you might try is turn off the LTFTs. Fuel dumping at WOT is difficult to control when LTFTs give you the run around.

Ed Blown Vert
10-18-2005, 12:16 PM
COT was turned off.

Your probably right on the OLFA. I just remembered that on a few pulls on the dyno. My AFR dropped to over 10:1 That must have been when it was using the PE table.

I never touched the OLFA table, how does it work??

MNR-0
10-21-2005, 03:24 AM
You really need to log your "Commanded AFR" PIDS as above to determine exactly what is happening. The OLFA table is used for part throttle (non WOT) in place of closed loopwhen closed loop is disabled. At WOT, you are still running open loop, so the VCM will take the richer of the 2 values (PE vs. OLFA) and use that.

What are your LTFTs doing at WOT? I recommend disabling them for all the trouble they are worth. Your car will still run fine switching off the STFTs and since you have HPT you can still dial in the fuel trims off that - infact - thats how I always do it.