I think I have a bad MAF.

Rustyregal

Member
Joined
Jun 7, 2012
This isn't a full pass as I do not have the space. But I would think the MAF should be under full load in a WOT first gear run. Anyway here's the numbers. I got on it then turned around and did it again.
 

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Would need to know the boost, but it looks like you don't have the MAP sensor connected.

Also, you have your WOT target A/F set to 12.2 in the chip. Are you sure you want it that lean?

Eric
 
I just got a couple of new logs. Blackgn1 I'm not sure. Any input will help as I'm a bit green but reading everything I can. Added some new grounds today,firewall to coil pack,firewall to valve cover,firewall to battery,all 10ga. I have a newly installed caspers cap and a spare of the same type. No matter what at WOT I am not seeing over about 220 on my MAF. Wouldn't that lean me out as the car may not be adding enough fuel? And my boost is around 14-14.5 psi.
 
Yes, the MAF is reading too low.
Since the MAF is not locked at 255, the timing won't be locked to a certain value.
I would replace the MAF, and reset the chip to the defaults so the target A/F is back to 10.8 for now.
Eric
 
Looking to get one tomorrow from a buddy that's a hardcore LS guy. I will give your suggestions a go for sure. Not everyday you see such good service after the sale Eric. So kudos to you man you have responded to every question I've had thus far. Best $125 bucks I've spent on my car. Question though would having my AF set to the 12.5 I have now guard against knock better even though I would suffer in performance? Still trying to get a grasp on all of this.
 
I understand that 12.5 is lean compared to stoichiometric 14.7. My TT chip has. Max setting of 12.5. The reason I proposed the question was due to my chip burners request to set it back to an even leaner 10.8. But thanks for the input all the same.
 
Eric Stage I said:
Yes, the MAF is reading too low.
Since the MAF is not locked at 255, the timing won't be locked to a certain value.
I would replace the MAF, and reset the chip to the defaults so the target A/F is back to 10.8 for now.
Eric

Not to hijack but how do u go
About reading higher than 255?
 
Rustyregal said:
So do I have this whole AFR thing backwards? :

10.8 is richer than 12.5?

Yes 10.8 is richer than 12.5. Lower the number the richer the afr and the higher the number the leaner the afr
 
Rustyregal said:
I understand that 12.5 is lean compared to stoichiometric 14.7. My TT chip has. Max setting of 12.5. The reason I proposed the question was due to my chip burners request to set it back to an even leaner 10.8. But thanks for the input all the same.

He might be talking about setting it to 10.8 under WOT and boost. That's about where you'd want it. Just crushing around normal 14ish is what you should get
 
So do I have this whole AFR thing backwards? :

10.8 is richer than 12.5?

Air:fuel....11.4 AFR is 11.4 parts air to 1 part fuel. You should be around high 13's at idle, 14.4 or a little higher (like 15-16) while cruising, and 10.8 or so at WOT.
 
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