Is my tune f****** up or my o2 sensor is ?
Oct 24, 2009, 04:39 PM
#1
Is my tune f****** up or my o2 sensor is ?
PLEASE READ I NEED HELP !!!!!!!!!! THANKS
I need help fast . I got my evo tuned on the stock ecu 2 months ago everything was perfect the car ran strongs I made 560whp on e85 @ 33 psi on 35r and the a/r ratio would always be 11.9 all the way to red line. I didn't race the car for 3 week's last night I wanted to race and as soon as I floored it I realize that a/f went to 12.8 by 7k I new something was wrong I cheked for boost leaks found nothing , I also checked for fuel leaks nothing , my fpr pressure was at 45 I raised it up to 55 and did a 3 gear pull and the a/f was 12.6 and the higher I rev it the leaner it got .... I lowered the boost to 30psi and the a/f was still 12.9-13's
Is my tune messed up or is my wideband o2 sensors not reading correctly please help? WHAT CAN I DO ABOUT THIS PROBLEM? THANKS
I need help fast . I got my evo tuned on the stock ecu 2 months ago everything was perfect the car ran strongs I made 560whp on e85 @ 33 psi on 35r and the a/r ratio would always be 11.9 all the way to red line. I didn't race the car for 3 week's last night I wanted to race and as soon as I floored it I realize that a/f went to 12.8 by 7k I new something was wrong I cheked for boost leaks found nothing , I also checked for fuel leaks nothing , my fpr pressure was at 45 I raised it up to 55 and did a 3 gear pull and the a/f was 12.6 and the higher I rev it the leaner it got .... I lowered the boost to 30psi and the a/f was still 12.9-13's
Is my tune messed up or is my wideband o2 sensors not reading correctly please help? WHAT CAN I DO ABOUT THIS PROBLEM? THANKS
Last edited by Dragking2189; Oct 24, 2009 at 04:47 PM.
Oct 24, 2009, 05:53 PM
#4
no misires at all ... the car pulls hards it just that the wideband shows 12.6-13's a/f ratios. could it be that the sensor on the aem wideband is bad? I also changed the plugs and drained the tank and filled it up with fresh e85?
Oct 24, 2009, 06:12 PM
#5
The difference in temperatures can create AFR swings of 1.0 point or more. It's possible that colder, denser air is making the car run that much leaner.
If you've been getting your fuel from the same station, it's unlikely the fuel to blame, as E85 is usually about 80% Ethanol in summer months and 70% Ethanol in winter months, but it varies depending on state & source. If you were tuned on higher percentage Ethanol, and the station switched to a lower percentage, your tune would have gotten richer, not leaner.
A boost leak would not be to blame either for a leaner mix, only a richer one.
Leaning out towards the top end implies a fuel flow limitation. What's your fuel pump setup? If you have a double pumper, you may be operating on only one pump.
If you've been getting your fuel from the same station, it's unlikely the fuel to blame, as E85 is usually about 80% Ethanol in summer months and 70% Ethanol in winter months, but it varies depending on state & source. If you were tuned on higher percentage Ethanol, and the station switched to a lower percentage, your tune would have gotten richer, not leaner.
A boost leak would not be to blame either for a leaner mix, only a richer one.
Leaning out towards the top end implies a fuel flow limitation. What's your fuel pump setup? If you have a double pumper, you may be operating on only one pump.
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