Questiong regarding MAF and running Lean
Questiong regarding MAF and running Lean OK, so my FI car (99 C5 Non-intercooled Maggie) was running lean on the Dyno. Installed a Kenne Bell boost a pump to keep the FP up around 58 or so PSI. No difference. Then for grins I disconnected the MAF and bamm!! MY AFRs come down from 13.5 to 12.1 to 11.8, perfect. sooo, what the heck is wrong with the MAF? Do I have a bad MAF or are the settings in the VE table incorrect? More importantly, how the heck does one go about troubleshooting this issue?
TECH Enthusiast
Joined: Mar 2003
Posts: 618
Likes: 0
From: San Diego
Either your MAF is bad or you need to recalibrate your MAF. Log MAF frequency and LTFTs and adjust MAF table accordingly.
Since the lean condition only appeared when your MAF was plugged in and dissappeared when unplugged that pretty much narrows it down. I'd wager it was never calibrated correctly when tuned.
Since the lean condition only appeared when your MAF was plugged in and dissappeared when unplugged that pretty much narrows it down. I'd wager it was never calibrated correctly when tuned.
Is your MAF a 3 wire, or a 5 wire. If it is a 5 wire then it has the temp sensor in it. and when I unplugged mine it defaults to -38* and added a ton of fuel to compensate for what it though was really cold air. This might be what your seeing.
Originally Posted by kbracing96
Is your MAF a 3 wire, or a 5 wire. If it is a 5 wire then it has the temp sensor in it. and when I unplugged mine it defaults to -38* and added a ton of fuel to compensate for what it though was really cold air. This might be what your seeing.
Can't wait to pickup my own tuning package. TECH Enthusiast
Joined: Mar 2003
Posts: 618
Likes: 0
From: San Diego
The problem is, your MAF might be fine.
A new MAF may not fix your problem. Are there any members near you with tuning software? I can tune 99 vettes in San Diego, but something tells me you aren't in SoCal
A new MAF may not fix your problem. Are there any members near you with tuning software? I can tune 99 vettes in San Diego, but something tells me you aren't in SoCal
Originally Posted by Bombguy99z28
The problem is, your MAF might be fine.
A new MAF may not fix your problem. Are there any members near you with tuning software? I can tune 99 vettes in San Diego, but something tells me you aren't in SoCal
A new MAF may not fix your problem. Are there any members near you with tuning software? I can tune 99 vettes in San Diego, but something tells me you aren't in SoCal
I got the tune from Magnuson, so I'm thinking they should have gotten the MAF calibration right, since they probably do like 100's of these. Looking for a tuner in my area that can log the MAF Feq's right now. I'm pinching pennys to get the new version of HPT, so hopefully this (lack of tuning softeware) will be a temporary issue. 
