LS1TECH - Camaro and Firebird Forum Discussion

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-   -   MAF Reading at Idle (https://ls1tech.com/forums/pcm-diagnostics-tuning/1906542-maf-reading-idle.html)

brootus 09-12-2018 07:29 PM

MAF Reading at Idle
 
Do you guys know what a typical MAF reading is at idle? I am getting 3.5-4.0 lb/min at idle currently. I am having some idle surging problems along with a slightly hanging idle. I though the MAF use to read 1.8-2.0 lb/min, so that’s why I’m concerned.

Btw my car is an LS1 with 243 heads, LS6 Intake and throttle body, stock Maf (brand new) and a Tick SNS Stage 3 cam (235/243, .630/.610).

brootus 09-13-2018 12:24 PM

So I tested the wires at the MAF connector and they have 11.75v on the pink wire and 5.1v on the pcm wire. And they middle ground wire is giving me an appropriate ground on my meter.

So so I went and bought a new maf from autozone, duralast brand. And I’m getting the same reading, 3.4-4.0 lb/min or 25-30 grams/sec. so apparently it wasn’t the maf that’s the problem. The idle speed is at about 1000 rpm in Park and about 900 rpm in drive btw.

Any input on if these values are normal would be helpful. Thanks.

Main One 09-14-2018 08:29 AM

I'm about 1.8 lb/min on my LS1 but with a smaller cam, 228/230, lift around .58 but with 1.8 rockers lift more around .615.

fst100 09-14-2018 08:39 AM

wish I could help but I usually read my MAF using the frequency/hrtz which at idle fluctuates around 2700-3000 in gear/neutral.

brootus 09-14-2018 09:19 AM

Thanks guys, I wish I knew what the rate is in hz. I bought a OBD2 dongle on eBay that plugs in the OBD2 port and syncs with an app I bought on my iPhone. OBDFusion is the app. I can monitor a lot of data in real time on my phone while the car is running. But I can only monitor the mass air flow rate in lbs/min. 1.8 lbs/min seems about right to me, I appear to be about double that.

fst100 09-14-2018 09:35 AM

if you have the torque app or if the OBDFusion allows to add custom PID I can give you the PID and formula to register the hertz parameter.

brootus 09-14-2018 10:16 AM

That would be very cool if you don’t mind. I haven’t played with the OBDFusion app very long so I’m not sure if you can create custom PID’s. If you don’t mind giving the formula I can try to create it though. Thanks a lot.

fst100 09-14-2018 10:30 AM

sure np. posting here in case it may help someone else in the future:
PID: 221250
Long Name:
Short Name: MAF
Min Value: 0.0
Max Value: 11500.0
Sale factor: x1
Unit type: hrz
Equation: ((A<8)+B)/2.048
OBD header to use: auto


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