Rough running

[Hog]

Originally Posted by Billy Mild

Tonight I did a little more driving with my old school Snap-On MT2500. I set the lights for Closed Loop, Port Throttles closed, and Knock detection. For the the first time since this started I have a common thread, when the stumble occurs after decel, when the car is around 2000ish RPM and I give the car 30-40% throttle, the knock light goes ON, and the car stumbles, the secondaries appear to open as well. Very interesting IMO. So I believe it is due to a knock being detected, now I don't know if there really is a knock.

Unfortunately I don't have a stock chip anymore. Would it be worth test driving with a stock 91 chip to see if anything is different?

Mr Mild, you say you are getting some knock sensor activity when you open the throttles suddenly?
I wonder if you are getting some "Burst Knock"? Burst knock usually occurs during heavy throttle transitions. Some calibrations will pull ignition timing advance in these areas to avoid the real knock.
Could also be some lean knock with all the extra air rushing in with the sudden opening of the t-body throttles and Port throttles opening up quickly. In this case some extra Acceleration Enrichment could help?
Just some brainstorming on my part.