What should the MAF sensor read at idle? Ive heard 40 g/s but mine is reading 37-38 ish at idle with an LMM intake on my LLY. I had to modify the LMM intake to fit the lly maf sensor, so I'm not sure if it should read exactly 40g/s or not
MAF at Idle?
- Thread starter cstephens93
- Start date
I feel like the throttle response can be iffy at times. But before you say anything, I have tuning by Idaho Rob and he said his tunes support the LBZ intake, so the MAF should be rescaled already.
Before when I had the LLY airbox, my MAF read about 70-80 g/s, now with the LMM airbox, it reads closer to 40 g/s
70-80g/s sounds high for any Duramax engine at idle. 40g/s sounds roughly correct. I feel like where your vanes are at an idle can change that reading as well.
The MAF should be 40 but most trucks will vary 38-41. It will never hold steady at 40. AS long as you are not seeing less than 35-36 as the norm your truck will feel and run like it should. The 70-80 you previously had was wrong for sure.
Shane what was funny, is the 70-80 was showing on my LLY airbox. ATP said their race tuning will run with either airboxes with no tuning adjustment made
The reading you get comes from the interworkings of three items. First it uses the velocity if air flow. The ecm uses a voltage to the MAF. Finally the air cools the heat applied to the MAF which in turn gives a analog signal that is interpreted into a number reading. That 70-80 number had more velocity which is evident from that reading in itself. There is or was a difference in sizing of some parts involved that resulted in that velocity change.
Well yeah the diameter on the LMM/lbz box is bigger than the lly airbox ? Am I correct? That's what ive always been told since ive never actually measured the two
It's all about how it effects the velocity of the air. Bigger pipes etc. Will slow the air down. Without recalibration you will see lower numbers than before the changes. When you start getting readings below 35 you will start to see a truck that is laggy sluggish feeling.
It wasnt smokey. I was just confused because so many people say when you switch airbox's you need to have the MAF rescaled by your tuner.
Rob at ATP knew I had the LLY airbox, then i told them I was switching to the LBZ airbox and said i needed the maf rescaled and he said there was no need because his tuning works with both airboxs