Closed loop breaking up
Jun 20, 2017, 01:28 AM
#31
I've got the MAP sensor logged. It could definitely be the scaling though. It seems to be outputting a good number in the log, but it's not an officially supported MAP sensor. Corbin (my tuner) made a scaling for it that he said would work though. It's a GM 4 bar. I can't run a standard Evo map sensor because the JDM manifold doesn't have a provision for it. Tuning SD is one of those places where my knowledge is still lacking, so I'm not sure how to tell if the MAP sensor scaling could be the issue.
Jun 20, 2017, 07:59 AM
#34
Here's how I have it set up currently:
I'll probably pick up a GM 3 bar MAP since the scaling for that one has been set up in ECUFlash already and I've got the rest of the car set up to run a GM style MAP. It's just this oddball GM 4 bar that doesn't have a proper scaling. Basically this is an Omnipower GM 4 bar MAP. I had originally assumed that the Evo Omnipower 4 bar MAP would have the same scaling when I ordered it. When I got the car to the tuner I found out this wasn't the case. He said it would work though and made a scaling for it using custom "SD MAP Sensor VE and Calibration" numbers and the setting for the Omnipower Evo style 4 bar. I think it's definitely a possibility that that's what the problem is. The bin file is the standard one for Tephra v7. No custom scripts added.
I'll probably pick up a GM 3 bar MAP since the scaling for that one has been set up in ECUFlash already and I've got the rest of the car set up to run a GM style MAP. It's just this oddball GM 4 bar that doesn't have a proper scaling. Basically this is an Omnipower GM 4 bar MAP. I had originally assumed that the Evo Omnipower 4 bar MAP would have the same scaling when I ordered it. When I got the car to the tuner I found out this wasn't the case. He said it would work though and made a scaling for it using custom "SD MAP Sensor VE and Calibration" numbers and the setting for the Omnipower Evo style 4 bar. I think it's definitely a possibility that that's what the problem is. The bin file is the standard one for Tephra v7. No custom scripts added.
Jun 23, 2017, 07:06 PM
#39
Just a thought. You mentioned you deleted your pcv, and added a catch can. That's great but if done incorrectly then that's your issue.
did you not add a check valve to the catch can loop? If not then it's a vacuum leak, so at cruise your fueling is all over because of that.
What are your trims like? I suggest putting the pcv back. You should have a line from your intake manifold going to the can and also another from your pcv going to it. And cap the vent. This way you don't bleed crankcase pressure.
Hope this input helps, something mechanical cannot be diagnosed over a computer, but it's an idea for you! Good luck!
did you not add a check valve to the catch can loop? If not then it's a vacuum leak, so at cruise your fueling is all over because of that.
What are your trims like? I suggest putting the pcv back. You should have a line from your intake manifold going to the can and also another from your pcv going to it. And cap the vent. This way you don't bleed crankcase pressure.
Hope this input helps, something mechanical cannot be diagnosed over a computer, but it's an idea for you! Good luck!
Jul 5, 2017, 04:40 PM
#40
PROGRESS HAS BEEN MADE. So today I realized that my fuel trims and my timing advance are both bouncing around consistent with the misfire. Tried unplugging the knock sensor and the CAS to see if it would make a difference and nada. Timing advance is jumping between 5 and 18 degrees on the log. That would DEFINITELY make the engine react the way it is. Just gotta figure out why now...
Log is attached
Log is attached
Jul 27, 2017, 01:02 PM
#41
Changed the map sensor to an AEM 3.5bar unit and had my tuner set up the rom for it. Still have the same issue. Did a leak down test as well. All cylinders had less than 5% leakdown, however, I did notice that there's a bit of oil and a LOT of carbon on the piston tops. Definitely not normal for an engine with 3k miles on it since new. (this could also affect the leakdown test) Maybe the car is oil fouling from a leak or something. Intercooler is dry, so it shouldn't be the turbo, and I checked my valve seals as well. I seafoamed the cylinders directly and let them soak for an hour before drying them back out and reassembling the car. No change to how the car runs; but the piston tops look much better. Next I'll scope the intake manifold through the injector holes and see what I find. Shot a more concise video of the issue as well. Here it is:
Jul 27, 2017, 09:28 PM
#42
Evolved Member
If it is doing this only on idle and not on cruise and WOT runs then you should bare with it
and drive the car. Over the time if it gets worse then it will show up which part is causing this problem and easier to identify.
and drive the car. Over the time if it gets worse then it will show up which part is causing this problem and easier to identify.
Jul 28, 2017, 01:15 PM
#43
The problem is that is DOES do this cruising. The car kicks and bucks all over. Makes the car nearly undrivable and ruins the experience. It really beats you up! I did make another small discovery today. If you look in the video when the car gets up around 4k rpm the wideband is showing super rich in the 11.0-12.0AFR area. In the tune it's supposed to still be at a stoic 14.7AFR. I think this might be a big piece to the puzzle. Tried shortening the vacuum line from the MAP sensor just to see if it made a difference. It didn't other than tidying up the engine bay a bit.
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