Bad Mass Air????

[Dale G]

Is my mass air crapped out on me.
I was with my wife today in the car and floored it for a about 6 secounds. My AF went from 41-238-248-235 before I had to let off the gas and let my wife relax. I want to take it out tonight and get more frames on the scanmaster. My 02s will start at 800 and then drop drasticly down to 680mv, and knock is around 9.0.
Sometimes when I start the car it will backfire through the intake. My chip is unknown and my FP is set to 45psi line off. My Fuel pump is Brand new 340, fuel filter, power plate, wire's, hot wired,I'm also running Sunoco94. Any Ideas

 

[Dale G]

New numbers show up are 250,243,238,250,248,250, AF

 

[Eric Stage I]

It all depends on how much boost your running. At the typical pump gas setting of 15psi, its fairly normal to have maf readings in the 230-250 range. However, it does appear that it may be leaning out with the low O2 reading.
A quick, cheap fix to get the maf to peg 255 is to get a Thrasher chip for $25, which will force it to 255. That may give you a little more fuel, but only about 6-7%.
At least then you wouldn't have an unknown chip.

Regards,
Eric

 

[CanVan87GN]

Get the Thrasher

If you don't know what chip it is, the Thrasher is a cheap $25.00 fix to do like Eric said. E-mail Scott Simpson on this board and he can set you up. He was very pleasant to deal with and I am very happy with the chip. From there, start tuning and enjoy!!!


Shaun

 

[Dale G]

Thrasher chips are already on their way. So even if my Maf are not at 255 I still will have a problem with my o2's being around 700-690. How long should it take the mass air to get up to 255, 10-11-12-13 secounds?

 

[Eric Stage I]

As soon as you pass about 15psi it should be at 255. With a stock turbo it won't take very long, probably no more than a second after you mash the pedal.

Eric