Hi all,
Not sure if this is tune related are not but any help is appreciated. 2011 GT500 with KB 2.8. Started getting a misfire at transition throttle, usually in the mid 2k RPM range. I find P035x soft and hard codes (Ignition Coil <cyllinder> Primary/Secondary Circuit Malfunction) thrown when the misfire is felt and I feel it probably worse because I am sure the PCM is cutting the injectors to save the cats and not dumping raw fuel into the cylinders. This code has shown on a variety of different cylinders.
Some other conditions noted are that this usually only happens not long after a cold start in the cool morning and within the first 10-15 minutes of driving. In the heat of the day or after a hot drive cycle it does not seem to misfire and throw those codes. When the misfire happens I am usually cruising on the border of accel/decel, the engine then runs rough. I can let off the throttle or push in the clutch to let it go back to idle and the problem clears up. Just the other day I noticed I can also make this happen by revving the engine in neutral to 2500 RPM steady and holding it there and will start to here the miss in the exhaust (popping) and then it will run rough when the injectors are cut.
The reason I mention a possible tune relationship is I have had to work out with the tuner a previous bogging issue when stepping on the gas from transition throttle and it seems funny that this issue of misfire is only occurring during transition throttle. Tuner believes this issue is unrelated.
So this code points to bad COPS or a wiring issue between COPS and PCM but it seems funny that it only occurs in the situations described above and that so many of them went bad at the same time. Car has 16,500 miles only. Changed plugs and old plugs looked fine. Any other ideas why this could be happening before I incur the expense of replacing all the COPS or tearing into harnesses? Suggestions on diagnostic procedure?
Thanks in advance!
Not sure if this is tune related are not but any help is appreciated. 2011 GT500 with KB 2.8. Started getting a misfire at transition throttle, usually in the mid 2k RPM range. I find P035x soft and hard codes (Ignition Coil <cyllinder> Primary/Secondary Circuit Malfunction) thrown when the misfire is felt and I feel it probably worse because I am sure the PCM is cutting the injectors to save the cats and not dumping raw fuel into the cylinders. This code has shown on a variety of different cylinders.
Some other conditions noted are that this usually only happens not long after a cold start in the cool morning and within the first 10-15 minutes of driving. In the heat of the day or after a hot drive cycle it does not seem to misfire and throw those codes. When the misfire happens I am usually cruising on the border of accel/decel, the engine then runs rough. I can let off the throttle or push in the clutch to let it go back to idle and the problem clears up. Just the other day I noticed I can also make this happen by revving the engine in neutral to 2500 RPM steady and holding it there and will start to here the miss in the exhaust (popping) and then it will run rough when the injectors are cut.
The reason I mention a possible tune relationship is I have had to work out with the tuner a previous bogging issue when stepping on the gas from transition throttle and it seems funny that this issue of misfire is only occurring during transition throttle. Tuner believes this issue is unrelated.
So this code points to bad COPS or a wiring issue between COPS and PCM but it seems funny that it only occurs in the situations described above and that so many of them went bad at the same time. Car has 16,500 miles only. Changed plugs and old plugs looked fine. Any other ideas why this could be happening before I incur the expense of replacing all the COPS or tearing into harnesses? Suggestions on diagnostic procedure?
Thanks in advance!
