MAF cutting out? (powerlogger file inc)

[jamiegallien]

I posted this on the Turbotweak forum too, but wonder if any of you might have input.

87, stock except for 42lb injectors, K&N, FP @ 43psi static, 14lb boost, on 93.

The MAF jumps from 255 to 225 constantly in PE mode. I thought the chip tricked the computer into seeing 255 no matter what. I'm wondering if this is indicative of a bad MAF and the chip couldn't cover for it?

Also, that little bit of knock in 2nd gear but it goes away...what could that be at 14 lb?

One other thing, the P/N indicator lights just before full boost comes in. Something loose under the car maybe?

Thanks for any insight!

Jamie

 

[ITSAV6]

I always thought the maf "locked" to prevent maf dropout like the stock chip does.

 

[jamiegallien]

That's what I thought, but I'm not sure it means what I think it means. Here is a screenshot so folks don't have to load the log just to see it.
I'm sure it's something with my car, the TT chip has been great so far.

 

[Boost231]

MAF is fine. That's the reading you will see it will never be locked 255.

Sent from my SM-N930T using Tapatalk

 

[SCOOBY DOO]

Your battery voltage drops to 12.6 at WOT. I'd suspect the KR you're seeing might be caused by insufficient voltage to the pump.

 

[jamiegallien]

MAF is fine. That's the reading you will see it will never be locked 255.

Sent from my SM-N930T using Tapatalk

Eric (turbotweak) explained it on his forums. The computer uses 255 to do it's calculations, but the powerlogger reading shows actual.

Your battery voltage drops to 12.6 at WOT. I'd suspect the KR you're seeing might be caused by insufficient voltage to the pump.

I hadn't noticed that. Strange that I have a new AC/Delco alternator and hotwire to the pump. No reason at all for the voltage to be low, esp at higher rpm. Yet another thing to look into....

 

[SCOOBY DOO]

For shits and giggles, check the voltage at the back of the alternator.

 

[aminga]

The PL get's the voltage reading from the ECM feeds it's a small gauge wire it won't show the same voltage as the back of the ALT