What should SR20 z32MAF IDLE voltage be? (contains ECU logs)

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MJD5SS
 

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Joined: Wed Apr 17, 2013 6:24 pm

What should SR20 z32MAF IDLE voltage be? (contains ECU logs)

Post by MJD5SS »

Car: Nissan Pulsar N15
MAF: Z32
Injectors: 370cc
Turbo: T25
car has been tuned by CRD, was absolutely fine for about 8 months, now all of the sudden I have to keep tapping the throttle to hold idle while warming up. Once hot around 90 degree it idles like a dream! all problems gone.

-Removed cleaned and rebuilt IACV, also the AAC.
-No boost leaks.
-Base idle adjusted.
-TPS 0.45v
-ECU throwing code 12 AFM

Only way it will idle is if I completely screw in the idle screw and adjust the throttle stop screw so that the IACV is not being used.

I conducted a log and guess what I found, MAF voltage looks low? could that be the reason? after 7 months and a lot of friggin' around & shit cold idle.

Ignition ON:
Image

Cranked over:
Image
Image

Full logs can be viewed here:

Start + Idle + little rev https://docs.zoho.com/file/1m466f465e4e ... a65b383a9b

Key ignition ON https://docs.zoho.com/file/1m4665abfb64 ... aa18d58f42

I also throw MAF fault code too every now and then

http://www.youtube.com/watch?feature=pl ... Uf6TIW1xMA
unreal-
 

Posts: 49
Joined: Mon Dec 30, 2013 5:46 pm

Re: What should SR20 z32MAF IDLE voltage be? (contains ECU l

Post by unreal- »

If its throwing a MAF code, replace the MAF :?:
MJD5SS
 

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Re: What should SR20 z32MAF IDLE voltage be? (contains ECU l

Post by MJD5SS »

Just weird because it drives on boost and off just fine?

cheers for the input.
unreal-
 

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Re: What should SR20 z32MAF IDLE voltage be? (contains ECU l

Post by unreal- »

MAFs can be weird creatures sometimes and tend not to make much sense when they go bad. Do you have any screenshots of the MAF at higher RPM/load? Those values look pretty normal for a maf at low rpm/throttle angle.
MJD5SS
 

Posts: 45
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Re: What should SR20 z32MAF IDLE voltage be? (contains ECU l

Post by MJD5SS »

nothing at higher load, I will do another test tomorrow and upload the results.
MJD5SS
 

Posts: 45
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Re: What should SR20 z32MAF IDLE voltage be? (contains ECU l

Post by MJD5SS »

Image

Hey again, this is the WOT squirt, and feel free to scroll through the log aswell, its around line 1000 on the spreadsheet.

https://docs.zoho.com/sheet/ropen.do?ri ... 7e19ce3037
unreal-
 

Posts: 49
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Re: What should SR20 z32MAF IDLE voltage be? (contains ECU l

Post by unreal- »

Looks pretty normal to me. MAF voltages at WOT seem to correspond with the amount of power you would be making with the T25 and that engine. At first i thought it was a little low (usually is over 4.0v at WOT) but that is when you start to push over 350whp. I forgot that MAF's voltages increase with the amount of air that flows through them. Since the Z32 MAF is good for around 500whp, Its not going to be pushing that much voltage at WOT because its not being used to full capacity.

If possible, i'd swap MAF's with a known good one to see if that fixes the problem and gets rid of the CEL.
MJD5SS
 

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Re: What should SR20 z32MAF IDLE voltage be? (contains ECU l

Post by MJD5SS »

ok I'll try
MJD5SS
 

Posts: 45
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Re: What should SR20 z32MAF IDLE voltage be? (contains ECU l

Post by MJD5SS »

Confirmed MAF is dead, I plugged my stock DE maf in, and its double what it was with the Z32, Started it from 45 degree coolant temp, didn't miss a beat all the way up into the 90's. Wow idle is smooth as now!! car goes alot better and doesn't smell like raw fuel whilst idling too, Keep in mind I do run a test pipe.

Now the real test is tomorrow, dead cold start, I have good faith in this one.
MJD5SS
 

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Re: What should SR20 z32MAF IDLE voltage be? (contains ECU l

Post by MJD5SS »

WOOO FIXED!!!!!!!
unreal-
 

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Re: What should SR20 z32MAF IDLE voltage be? (contains ECU l

Post by unreal- »

hahaha glad you got it figured out :)


Now get another Z32 MAF and kick ass!
MJD5SS
 

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Re: What should SR20 z32MAF IDLE voltage be? (contains ECU l

Post by MJD5SS »

Nar I'm staying the standard Maf, car pulls harder.
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