2-3K RPM hesitation/bucking - logged

[86fun]

Hey guys,


Wondering if anyone with some experience looking at logs and tell me what they think about my log file.


After installing a S/C kit I'm getting part throttle low RPM hesitation/bucking. Even full throttle has hesitation in the same RPM range too actually.


I purposely drove up a slight incline and in a lower gear to help the log show what was happening in a longer period of time.


Notice at about 9 and 11sec the vehicle speed slows, then speeds back up slightly, this is when I was experiencing the hesitation/bucking. All other load points feel smooth.


The calibration used is a CARB tune provided by the manufacturer.


http://www.datazap.me/u/86fun/low-rp...ta=2-3-4-5-6-7


Thanks for any input!

[steve99]

Originally Posted by 86fun

Hey guys,


Wondering if anyone with some experience looking at logs and tell me what they think about my log file.


After installing a S/C kit I'm getting part throttle low RPM hesitation/bucking. Even full throttle has hesitation in the same RPM range too actually.


I purposely drove up a slight incline and in a lower gear to help the log show what was happening in a longer period of time.


Notice at about 9 and 11sec the vehicle speed slows, then speeds back up slightly, this is when I was experiencing the hesitation/bucking. All other load points feel smooth.


The calibration used is a CARB tune provided by the manufacturer.


http://www.datazap.me/u/86fun/low-rp...ta=2-3-4-5-6-7


Thanks for any input!

Yep something weird happening the afr goes rearly rich low 11 and the ignition timing goes negitive like -3 with very little change in engine load or throttle position.
Looks like some sort of failsafe trip or something in tune, but this might be caused by malfunctioning sensor or air\boost leak.

Send logs to tuner

[pandamancer]

Originally Posted by steve99

Yep something weird happening the afr goes rearly rich low 11 and the ignition timing goes negitive like -3 with very little change in engine load or throttle position.
Looks like some sort of failsafe trip or something in tune, but this might be caused by malfunctioning sensor or air\boost leak.

Send logs to tuner

FWIW, I concur. I looked at the log from the Edelbrock post and came to a similar conclusion. Vacuum leaks are where I would start.

Knock looks like it may be another concern. What fuel are you using?

[86fun]

California 91

[devtec]

I have the exact same problem... having the car checked for vacuum leaks today. will keep this thread updated.

Anyone else with the Edelbrock s/c having this problem?

[NotSoJDM]

Originally Posted by devtec

I have the exact same problem... having the car checked for vacuum leaks today. will keep this thread updated.

Anyone else with the Edelbrock s/c having this problem?

I did not have this issue when on factory CARB tune from Edelbrock.