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Old 11-15-2007, 04:16 PM   #1
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Default High MAF Output

Hey there,

Any of you tuning gurus know what could be causing my MAF output to be high? I've cleaned the MAF, swapped it for another, checked for vacuum leaks (I show -20 inches at idle), reset the idle speed (850) and double checked the timing (10BTDC jumpered). My Xede and Xmap software continue to show me at 26% load at idle. This ends up putting me at least two rows of cells up in my maps.

Any idea what mechanical issues would cause this?

Thanks,
-Jon
94 Classic Red
FMI/BEGI 4.2 w/T25(?) Turbo
FMII Intercooler
FM Turbo Exhaust/Cat
Xede
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Old 11-15-2007, 04:47 PM   #2
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Have you talked to BEGI about it? Not to many Xede users here. If you unhook the Xede do you still have the problem?
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Old 11-15-2007, 06:28 PM   #3
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Yeah, Stephanie's working on it too. However, I don't think it's an Xede problem.

Without the Xede hooked up and it's software running, I don't know what the MAF output % is. Guess I can check the factory manuals for test procedures re: the MAF.

-Jon
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Old 11-15-2007, 07:19 PM   #4
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Is it constantly high, or did it just throw a code after a run?

On the emanage, you can monitor MAF in and out.. Depending on the boost you're running, you might be maxing out the MAF sensor, and need to trim some MAF voltage and add some injector.

Can you datalog with your XEDE?
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Old 11-16-2007, 10:15 AM   #5
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boost leak could cause it. Turbo sucks in 1000CFM of air but 300CFM of it leaks out, only 700CFM reaches the motor.
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Old 11-16-2007, 12:30 PM   #6
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Starts out at 26% at idle - then goes up from there as revs and load increase.
Been looking for boost leaks - however, wouldn't that also give me a vacuum leak at idle?

-Jon
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Old 11-16-2007, 12:45 PM   #7
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Does the xede have anything like the jumpers for an emanage? I know with my emu the first time I started the car I got a high maf output code because I never changed the jumper for a mazda hotwire maf.
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Old 11-16-2007, 01:03 PM   #8
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Does it show voltage vs %.

On my NB, at idle, you'd see about 2 volts. At 6psi, I was very close to peaking the MAF, i was seeing about 4.55-4.6 volts.
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Old 11-16-2007, 02:21 PM   #9
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Quote:
Originally Posted by mx5jon View Post
Starts out at 26% at idle - then goes up from there as revs and load increase.
Been looking for boost leaks - however, wouldn't that also give me a vacuum leak at idle?

-Jon
Not necessarily. I've seen hose cracks that seal under vacuum and open under boost.
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