attaus
07-24-2011, 09:20 PM
I am so close to giving up. It idles perfectly, accelerates OK, and boosts fine. However when at 10% throttle it bucks and randomly goes lean over and over. It does not matter if this is closed or open loop. So.. the O2 sensor is NOT bad.
The setup is..
KA-T
Enthalpy tune
AEM UEGO
Fully built
I have tried the TPS.. the voltage is normal. With the TPS removed, it behaves very similarly, but the same problem persists.
The MAF is getting normal voltage. I'm seeing ~1.3V at idle. I can't see what it is under load but I would assume that it's normal. If I unplug the MAF with the car running, it will die immediately. If I try to start it again, it won't start.
The ECT is working normally, and the car will not start or run with it removed.
I'm seeing 14ish to 15ish at idle AFR's and about 13-14 under acceleration, less depending on throttle position. It has dipped down to 10-11 out of boost, so it's not lean under acceleration.
I recently redesigned the intake so that I have a 35 degree angled reducer to a 12x3" pipe with the MAF at the end of it, so it's not too close. I don't think that some weird vortex is causing this, but I guess it's possible.
I have never messed with IAT because I have not suspected it. It has not been touched and the car ran great before the new intake setup.
I am 99% sure it's not a fuel issue. Given that it accelerates, idles, and boosts just fine it can't be. Granted, whatever the issue it is causing a lean scenario it is not the fuel system itself, it is the control side.
Please help me. I have searched over and over and cannot find the solution. I have tested damn near everything. I don't think the MAF is bad. I know the wiring is OK because I have tested it and re-soldered it and tested it again. I don't think it's because of the new intake because the MAF is further from the turbo than it's ever been.
I can't pull codes. The ECU I was given only has one light, and I can't hook up a Consult.
The setup is..
KA-T
Enthalpy tune
AEM UEGO
Fully built
I have tried the TPS.. the voltage is normal. With the TPS removed, it behaves very similarly, but the same problem persists.
The MAF is getting normal voltage. I'm seeing ~1.3V at idle. I can't see what it is under load but I would assume that it's normal. If I unplug the MAF with the car running, it will die immediately. If I try to start it again, it won't start.
The ECT is working normally, and the car will not start or run with it removed.
I'm seeing 14ish to 15ish at idle AFR's and about 13-14 under acceleration, less depending on throttle position. It has dipped down to 10-11 out of boost, so it's not lean under acceleration.
I recently redesigned the intake so that I have a 35 degree angled reducer to a 12x3" pipe with the MAF at the end of it, so it's not too close. I don't think that some weird vortex is causing this, but I guess it's possible.
I have never messed with IAT because I have not suspected it. It has not been touched and the car ran great before the new intake setup.
I am 99% sure it's not a fuel issue. Given that it accelerates, idles, and boosts just fine it can't be. Granted, whatever the issue it is causing a lean scenario it is not the fuel system itself, it is the control side.
Please help me. I have searched over and over and cannot find the solution. I have tested damn near everything. I don't think the MAF is bad. I know the wiring is OK because I have tested it and re-soldered it and tested it again. I don't think it's because of the new intake because the MAF is further from the turbo than it's ever been.
I can't pull codes. The ECU I was given only has one light, and I can't hook up a Consult.