After my Lsa swap and getting the truck tuned the truck still has a slight stumble that my tuner couldn't get out when you 1st hit the gas but goes away the more throttle you give it.
Truck is a 5.3, Lsa blower swap making about 11lbs of boost. Just trying figure where to start looking/ troubleshooting

 

Do you have a wideband? If so what does the afr do?

 

Yes the aft was in the 15. 2 range and went down as I gave it gas and the stumble went away

 

Would a plug that was too cold cause that issue? I'm running a br7ef gapped at .032

 

That plug gap needs to be .025. The afr should be 14.7 at idle and cruising.

 

I'll tighten the gap up. And Cruising it's from 14.7 to 15.5. Would it matter if it was tuned for speed density, cause that's what the shop that tuned it did.

 

It's not tuned right if the afr is swinging that much. What it sounds like is a lean stumble on tip in.

My Whipple was speed density and the afr never went lean on tip in.

 

That's exactly what I'm experiencing. well after having it for almost a month for the tune and a few small unexpected issues they basically said that was the best they could get it. And that it was possibly a mechanical issue not a tune issue. And this was from a well known ls shop. So I guess My only option would be to take it elsewhere?

 

It is impossible to see exactly 14.7 on the wideband at all times, that small swing is more than fine if it following the o2 sensor switching at normal idle and cruise speeds.

 

sometimes it will go to the 16+ range..