Turbo car breaking up in and out of boost all the sudden.

[BlackWS666]

My turbo car just recently started acting up. Did a diagnostic on it by logging a cruise and noticed that O2 bank 2 sensor was reading funny. Replaced the O2 sensor with the same results so im positive the sensor is correct. Here is the log. What you guys think?

[BlackWS666]

Car feels like its chugging really hard when in the throttle. it has come out of it a few times for a brief moment. Im thinking its spark related, but i didnt have much time to start the diagnosing process. Just curious if any of you can tell from the log where a good place to start would be. Thanks

[Montecarlodrag]

Where is your wideband located?
The AFR under boost is very lean even for N/A engines, it may be the cause for the breakup.
The IDC seems low, which injectors do you have?

More information about your tune and setup would be of help, not much information in your datalogs since you are logging several useless PID's making frame rate slow for no reason

[BlackWS666]

THanks for the responds. Do you have a recommendation for how to make it log more frames? The injectors are high imp 160's. Wideband is in the downpipe right out of the turbo about a foot. Both of the O2 sensors are in the crossovers both 8" from the collectors off the reverse manifolds. When the car is running correctly it is usually 11.0-1 11.5-1 AFR from the wideband. 079-0.jpg

[Montecarlodrag]

Delete all unneeded PIDs from the main table, like fuel trims or mass airflow.
Post your tune.
You didn't go past 54% TPS for the run, you may not be entering PE. If you are entering into boost at that TPS levels you need to change some things

[BlackWS666]

I did some testing tonight. O2 sensors are working properly, plug wires are all good, no vacuum leaks. I did try to turn open and closed loop on and off threw the scanner and it pulled up some weird numbers. The STFT from bank 1 to bank 2 are way off. Here is the log i did tonight with it on closed loop. The driveability and idle seem to help a little once turned into closed loop, but overall the problem with it breaking up under any throttle is still present. Here is the log i did tonight and here is the tune.

The one that says good timing data is a previous log i did before the problem started. Just for reference.

Im also going to get a pyrometer tomorrow and see what the temps of each exhaust runner is, maybe i can pinpoint something. Thanks for the help.

[Montecarlodrag]

Are you still using the config from the first post? If you are then the data is useless 'cause you are logging MAF (thus skewing airflow measurement). Delete it and all trims from the main table and log again.
The "good timing" datalog clearly shows a much better AFR than first log, both O2 agree. That is one cause of the breakup, lean AFR

What did you change in the tune since the last good run? I would go back to the last known tune and test

[wyochimneysweep]

Bad tank of fuel?

[BlackWS666]

Ok Monte, i took out the MAF and the LTFT as i dont use ether. I will load my old tune that i did that test on and do another log. I thought about the fuel being shit possibly but ive had 2 new tanks since then.

Im about 90% sure it has nothing to do with the tune. Everything was running perfect then it started last weekend. Im going to try to switch to some new coil packs to be sure its not a faulty spark issue. Just wish i could pin point it down to at least a fuel or spark problem.

[BlackWS666]

Figured out the problem. I tested all the injectors with a noid light and they checked out. Then used a stethoscope to listen to the injectors and the #8 injector sounded really weak. Pushed on the clip and it lite back up. So i changed the clip out with a new one and wahlah. Problem solved. Bad injector clip.