mowton
December 1st, 2015, 03:12 PM
Evening all...I have been struggling with this Camaro for almost 2 months now and have just about run out of ways forward.....
Customer did the install and we have reviewed it thouroughly to make sure all is right and so far we have only found minor issues and have fixed them (i.e MAP sensor placement and type). Has a 232/236 on a 112 cam (9.5 degrees overls) and as delivered to shop, the tune was unusable (surging, stalling etc). Worked out most of the initial issues and began to tune the MAF. From the onset, the fueling was erratic (even for a newly flashed E38 :-)) and it seemed like we were chasing our tails. That is when we discovered a large difference in the 2 banks (eventually went from OL to closed loop). Tried open close loop, MAF only, speed density etc and all strategies yielded the same results. as you are "filling the boxes" during MAF scans, at approximately 4000 hz or so the wb/trims (depending on OL/CL) will slowing ramp to lean (15-20%) and then come back down to like 10-15% rich!!!!! The would result im "bumps" in the MAF curve if you tried to correct for them....very strange. The events occur closely at the same points in the scan each time and can ocurr in several different rpm/hz points throughout the scan as well.
Today we tried to "average tune" using the SFTF's (Closed loop with disabled LTFT) in closed tune to keep the trims away from the p0172/174 criteria and let closed loop correction take care of the anomaly and then plow forward to the wot tuning.....as luck would have it, the placement of the MAP wouldn't actually read boost, so we relocated back where it belonged and went to 5000 rpm. While PE activated right on schedule and the MAF/Dyn Air rose linearly, the injectors weren't commanded (in an instant) to their levels (10+ ms) for almost 2 secs.....meanwhile all PE delay settings were set to zero.
Here is the latest tune/half pull log as well as a few other logs to help. I am at my wits end and am hoping it isn't something stupid I missed. Let me know if you need anything else and thanks in advance for your efforts.
Ed M
1904919050190511905219053
Customer did the install and we have reviewed it thouroughly to make sure all is right and so far we have only found minor issues and have fixed them (i.e MAP sensor placement and type). Has a 232/236 on a 112 cam (9.5 degrees overls) and as delivered to shop, the tune was unusable (surging, stalling etc). Worked out most of the initial issues and began to tune the MAF. From the onset, the fueling was erratic (even for a newly flashed E38 :-)) and it seemed like we were chasing our tails. That is when we discovered a large difference in the 2 banks (eventually went from OL to closed loop). Tried open close loop, MAF only, speed density etc and all strategies yielded the same results. as you are "filling the boxes" during MAF scans, at approximately 4000 hz or so the wb/trims (depending on OL/CL) will slowing ramp to lean (15-20%) and then come back down to like 10-15% rich!!!!! The would result im "bumps" in the MAF curve if you tried to correct for them....very strange. The events occur closely at the same points in the scan each time and can ocurr in several different rpm/hz points throughout the scan as well.
Today we tried to "average tune" using the SFTF's (Closed loop with disabled LTFT) in closed tune to keep the trims away from the p0172/174 criteria and let closed loop correction take care of the anomaly and then plow forward to the wot tuning.....as luck would have it, the placement of the MAP wouldn't actually read boost, so we relocated back where it belonged and went to 5000 rpm. While PE activated right on schedule and the MAF/Dyn Air rose linearly, the injectors weren't commanded (in an instant) to their levels (10+ ms) for almost 2 secs.....meanwhile all PE delay settings were set to zero.
Here is the latest tune/half pull log as well as a few other logs to help. I am at my wits end and am hoping it isn't something stupid I missed. Let me know if you need anything else and thanks in advance for your efforts.
Ed M
1904919050190511905219053