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Old 04-03-2008, 06:33 AM   #152 (permalink)
TurboBob
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Default Re: MAFT Gen 2 - Anyone?

Quote:
Originally Posted by Drweldin View Post
Ok - here's what happens:
Car warm, I elevate idle by pedal up to 2000 or whatever....AFR goes to 17-19,
short term trim goes to 79.6% and stays...as does AFR.
because the airflow is really low at that RPM, the ecu thinks you are decellerating. and leans out the fuel. If it is troublesome, you will have to richen up this spot.



Quote:
Originally Posted by Drweldin
Let off pedal, let it idle down, trim goes to 100% for about 3 sec....then plumets to 32.8% (AFR 11's)...stays there for 10 sec....then jumps immediately to 120% (AFR still 11's).... basically stays there.....this is all repeatable if I elevate the idle, just starts all over....including the times at each event.....ideas??
your idle appears too rich, the O2 trim dives to its minimum to try to correct the problem, and since it is still rich after about 10 seconds, it gives up.
Try leaning the idle out some.

what are your regular trims reading? Remember, trims do not read straight percent, they read 4X of the actual fuel correction. So for a trim of 80 the ecu is pulling about 5%

Bob
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