are o2 millivolts accurate on scanmaster?

[quickbrick]

i keep getting between 830-860 readings at wot on my scanmaster. no matter how much i turn up or down the fuel pressure. i think its supposed to be closer to 750, right. im getting very little knock so that is ok. but that seems very rich to me.

 

[U1ARUNIT]

They will be as accurate as you can get on a scan tool.

I thought that with a Thrasher chip you should keep the FP set to 45#?

 

[quickbrick]

i do keep it at 45. i was just checkin to see if i lowered it a little if the o2s would go down. but they wont.

 

[TurboRegal84]

If the car is running Rich under WOT then instead of playing with the Fuel Pressure just increase the boost a pound or two.

As long as you have the octane for the increased amount of boost with O2's in the 850 range a few more PSI(boost) should bring it down.

 

[quickbrick]

thanks, ill give it a try

 

[Steve Wood]

If you have some knock now, for God's sake, don't turn the boost up unless you improve the octane.

 

[TurboRegal84]

Steve...850 is pretty Rich...it could be knocking from too much fuel.



A good test that I always do is I put in some Race gas...if that solves your knock problem then you know it is octane, and you cannot run that much boost.

Quick Brick....How many pounds of boost are you trying to run?

 

[87SFI]

Originally posted by TurboRegal84
Steve...850 is pretty Rich...it could be knocking from too much fuel.



A good test that I always do is I put in some Race gas...if that solves your knock problem then you know it is octane, and you cannot run that much boost.

Quick Brick....How many pounds of boost are you trying to run?

I thought knocking was from being too lean or too much boost.
George

 

[quickbrick]

when i first give it wot it jumps to 18psi, for some reason it falls to about 14psi(feels very weak) then raises to about 16. i made a thread about this a while back and i couldnt figure out why it was jumping around. it started doing this after i put the new turbo on. with the stock turbo it would spike to 18 then sit at 16.
the o2 millivolt numbers are the same though as when i had the stock turbo on. i would like to run 17 psi all the time, but from what ive heard thrasher has a quick spool on thier chips. and thats why it spikes like that, but i cant figure out why the boost is dropping off now.