Silver'nStripes
Member
This is gonna be a long one, so bear with me here. Started a little over a week ago, I wrapped up installation of an AEM failsafe wideband/boost gauge, kirkey seats, and aftermarket steering wheel. I previously had an analog boost gauge, so I basically pulled that gauge and wired the new on in it's place. Driver's airbag was removed with the steering wheel, and the airbag system fuse pulled.
Took the car out for a test rip, data logging boost and AFR for the first time. The car runs great, but the data logged values are off. That's an issue for another post, but I wanted to go out again and video the gauge to compare it to the logged values.
Driving around to warm the car up, and it stalls leaving a stop light. Unusual. Start the car, pull away, and it bucks through the intersection, generally running poorly. The wrench light and check engine light comes on and the car goes into limp mode. Throws the codes P2072, Throttle Actuator Control System - Ice Blockage Bank 1, and P0102, Mass or Volume Flow Sensor A Circuit Low. Also a random misfire on all cylinders and a misfire in cylinder 8, but that has been a longer running issue. Doesn't seem to follow the plug or coil pack for cylinder 8, but probably another issue for another post.
I had recently cleaned and re-oiled the air filter, so my first thought was that some oil got on the Mass Air Flow Sensor. Cleaned the sensor and cleaned and oiled the air filter with much less oil.
Went out again, car ran fine at cruise and under partial boost. Under WOT at about 4,000 rpm in 3rd gear the engine falls on it's face, wrench light on, back in limp mode, same codes. Recorded data logs, but fat fingered the wrong keys and deleted them. Cleaned the inside of the intake tube and MAF again, thinking there was residual oil.
Next test drive, with a data log the codes threw almost immediately. Tracking every throttle body and MAF data point I can, as well as fuel trims etc. Data logging MAF Counts, it flatlined to 0.00 when it went into limp mode. Repeated this a second time after clearing the codes. Replaced the mass air flow sensor thinking for sure I had it figured out.
That brings us to today. Car runs fine at cruise, but under partial boost there is heavy hesitation around 4,000 rpm. In the time of hesitation before I lift short term fuel trims dive, then spike, similar in both banks. Timing generally has a spike. Nothing overly suspicious from the knock sensors, but I've never been able to glean good information from them. I remember seeing AFR jump to 18:1 on the gauge, though the data log doesn't reflect this extreme of a spike. Nothing unusual about fuel pump duty cycle.
As I'm writing this and reviewing the logs MAF data momentarily drops to 0.00 during the hesitation. Not like before where it flat lined for minutes as a time, but this seems strange to me. Any ideas here?
The values for throttle position sensor (TP1, TP2) and throttle blade angle (ETC throttle position and ETC throttle angle commanded) seem how you would expect.
Sorry for the small book here, but I'm really at a loss here. Trying to give as much detail as possible. If anyone has ideas of what data to look at or where to look next I'd really appreciate it. I'm thinking O2 sensors or maybe a vacuum leak, but I'm not sure here. Thank you in advance!
Took the car out for a test rip, data logging boost and AFR for the first time. The car runs great, but the data logged values are off. That's an issue for another post, but I wanted to go out again and video the gauge to compare it to the logged values.
Driving around to warm the car up, and it stalls leaving a stop light. Unusual. Start the car, pull away, and it bucks through the intersection, generally running poorly. The wrench light and check engine light comes on and the car goes into limp mode. Throws the codes P2072, Throttle Actuator Control System - Ice Blockage Bank 1, and P0102, Mass or Volume Flow Sensor A Circuit Low. Also a random misfire on all cylinders and a misfire in cylinder 8, but that has been a longer running issue. Doesn't seem to follow the plug or coil pack for cylinder 8, but probably another issue for another post.
I had recently cleaned and re-oiled the air filter, so my first thought was that some oil got on the Mass Air Flow Sensor. Cleaned the sensor and cleaned and oiled the air filter with much less oil.
Went out again, car ran fine at cruise and under partial boost. Under WOT at about 4,000 rpm in 3rd gear the engine falls on it's face, wrench light on, back in limp mode, same codes. Recorded data logs, but fat fingered the wrong keys and deleted them. Cleaned the inside of the intake tube and MAF again, thinking there was residual oil.
Next test drive, with a data log the codes threw almost immediately. Tracking every throttle body and MAF data point I can, as well as fuel trims etc. Data logging MAF Counts, it flatlined to 0.00 when it went into limp mode. Repeated this a second time after clearing the codes. Replaced the mass air flow sensor thinking for sure I had it figured out.
That brings us to today. Car runs fine at cruise, but under partial boost there is heavy hesitation around 4,000 rpm. In the time of hesitation before I lift short term fuel trims dive, then spike, similar in both banks. Timing generally has a spike. Nothing overly suspicious from the knock sensors, but I've never been able to glean good information from them. I remember seeing AFR jump to 18:1 on the gauge, though the data log doesn't reflect this extreme of a spike. Nothing unusual about fuel pump duty cycle.
As I'm writing this and reviewing the logs MAF data momentarily drops to 0.00 during the hesitation. Not like before where it flat lined for minutes as a time, but this seems strange to me. Any ideas here?
The values for throttle position sensor (TP1, TP2) and throttle blade angle (ETC throttle position and ETC throttle angle commanded) seem how you would expect.
Sorry for the small book here, but I'm really at a loss here. Trying to give as much detail as possible. If anyone has ideas of what data to look at or where to look next I'd really appreciate it. I'm thinking O2 sensors or maybe a vacuum leak, but I'm not sure here. Thank you in advance!