i have a 2009 gmc canyon with the 5.3 engine, just recently added a tvs1900 from magnuson. using the tune from magnuson.
1" 7/8 longtube headers and dual 3" exhaust.
multiple times the truck has hesitated under different points of acceleration. a few times in 3rd and some in first at about 2000rpm (just rolling out of the driveway)
i ran the truck at the track and didnt have a single issue at full throttle through the 1/4 mile. did 4 passes back to back almost.

when the issues occur then truck stops making power and hesitates/spits/spudders for a few seconds then stops and runs fine.

just trying to trouble shoot some possible issues.

 

by the way its only been on for a few hundred miles.

 

The tune could benefit a lot from being worked be someone in person. The canned tunes are very safe and generic. Sounds like a rich misfire.

 

it kinda feels like a carbureted engine.. spits spudders then hauls ***

 

Yep, just need to jet down a little

 

Hey there - the tune we provide with the kit is an emissions legal tune that works with the stock airbox, manifolds, and exhaust. You can sometimes get away with using our tune with a cat-back or shorties, but definitely not long-tubes. You're going to need to have the truck custom tuned, and I wouldn't drive it hard in the meantime. Your fueling is going to be way off.

Let us know your zip code or city, and we (and other forum members) can recommend some dyno tuners in your area.

- Matt @ Magnuson

 

49080

 

I just got a 3.4" pulley for the s/c . The truck will go on the dyno hopefully this week and hopefully we will find and or fix any of the issues finally..

 

what did you run at the track?