Riddle me this......OLSD Tune Weirdness
06-26-2016, 07:14 PM
#1
Riddle me this......OLSD Tune Weirdness Twin turbo, baby cam, 377 short, ported 317's, 95lb injectors (LOW base pressure of about 32 at idle, 26-28 cruising by design by previous owner/tuner), FAST 102 (opened and sealed by previous owner). OLSD tune which is what is confusing me with this issue.
Car has been good for the most part since I got it back, no tuning or mechanical issues cropped up. Had it out for some joyriding with some friends where I made a couple of long extended highway pulls, no issues noted. Then last month when I took it to SCT in Indy I noticed on the highway that my wide band, installed in the drivers bank behind the turbo, started running at 10.0 at cruise, and when I lifted the throttle, it would come up to the 13.8 to 14.2 range. Coming home later that evening, it was 13.8 to 14.2 at cruise and would dump to 10.0 when I lifted the throttle, then about an hour into the drive, everything flipped again. Drivers exhaust tips were all sooty and passenger side were clean. All four drivers plugs were pitch black fouled and passenger side looked fine to a touch lean.
Tossed my scanner on it and was watching the O2 switching and right side was switching fine, left side was only switching from about 80 to 300mv.
I can't find anything on the car to point to what's causing this, and can't really think of anything that could readily cause it considering it's an OLSD tune and not using O2 feedback for fueling.
Looking for some thoughts or advice. Other than this the car is running fine. I'm thinking of pulling and opening the FAST 102 to see if it was/is leaking internally.
Car has been good for the most part since I got it back, no tuning or mechanical issues cropped up. Had it out for some joyriding with some friends where I made a couple of long extended highway pulls, no issues noted. Then last month when I took it to SCT in Indy I noticed on the highway that my wide band, installed in the drivers bank behind the turbo, started running at 10.0 at cruise, and when I lifted the throttle, it would come up to the 13.8 to 14.2 range. Coming home later that evening, it was 13.8 to 14.2 at cruise and would dump to 10.0 when I lifted the throttle, then about an hour into the drive, everything flipped again. Drivers exhaust tips were all sooty and passenger side were clean. All four drivers plugs were pitch black fouled and passenger side looked fine to a touch lean.
Tossed my scanner on it and was watching the O2 switching and right side was switching fine, left side was only switching from about 80 to 300mv.
I can't find anything on the car to point to what's causing this, and can't really think of anything that could readily cause it considering it's an OLSD tune and not using O2 feedback for fueling.
Looking for some thoughts or advice. Other than this the car is running fine. I'm thinking of pulling and opening the FAST 102 to see if it was/is leaking internally.
06-27-2016, 10:11 PM
#3
Will do, and I'll go over all the grounding points as a backup. It's perplexing to me because of exactly what you said. The PCM isn't commanding it. Is this something that an airflow issue could potentially affect? As in a internally leaking FAST manifold? Or would that be more likely to be even across both sides? I'm tempted to just slap a LS2 and 90mm setup on the car to see what happens.