My 2006 Supercharged SS stumbles on part throttle &full throttle acceleration. Not quite a full-blown misfire, but close. Dealer says diagnostic tests reveal no problems, but the motor feels like crap now when accelerating.He says to stop using premium fuel and switch to regular, as I now have caused carbon deposits. Sounds fishy to me.
Has anyone else come across this problem of engine stumbling?

 

WTF! 93 causes carbon build up? get away from that dealership now. need more info of mods and when its doing it, but your problem can be solved here

l8r,
PD

 

this could be a lot of things, need more info...

dirty maf, clogged air filter, bad plugs, o2 sensors, clogged cat...list goes on

 

Try cleaning the throttle body.

 

those

 

whatever u do dont stop using 93 octane

my car feels stumbly too sometimes, does it happen when ur in really low rpms like 1-2k

 

my car does this in the higher rpm in 4th and 5th. I have to do some maintenance on it. Clean maf, TB, change plugs, Possibly seafoam, Change filter. Chances are one or a combination oif these are the culprit!

 

I have the same model, doing the same thing, no CEL, no mods, TB clean, cat is good, spark plugs are good, had a mechanic take a quick look, hes stumped too.

 

The car has zero mods....completely stock. 25k easy miles. Car never raced or abused (apart from not being garaged). Services performed were "Recarbonization Engine SBC", "Fuel Induction Kit" (throttle body cleaning I believe), and replaced Mass Airflow Sensor. However, dealer documentation records that a) they couldn't duplicate the problem (I believe it's impossible NOT to duplicate it), and b) they could not identify any problems after tunning diagnostic checks.
When we returned several weeks later reporting no improvement, we were told that we were using g "cheap" fuel (I.e., Costco), and that we should stick to a reputable filling station and stay with it. After several weeks we returned reporting no improvement, and were then told that the 93 Octane fuel we'd used since Day 1 too high, leading to carbon deposits, and that we should switch to "regular" fuel.

 

Ya don't listen to them about NOT using 93 octane. The car is a Force induction engine and using a lower octane will cause Knock. Best bet would be to change out the plugs with the proper gap and see how that does. My car had a little hesitation but once I took the old plugs out (gapped at .060mm) and gave them the proper gapping it has gone away.

 

if you have a CAI, clean it/recharge it. worked for me..

 

Yep. I'm still getting a minor Hesitiation in the 1,000-2,000 RPM range, Not half as Bad as when I had my exhaust Leak, But its still there. I did buy some new NGK's about 1-2 months ago and never Gapped them, So with my MOD's what would one recommend? Thanks