car feels like misfire... help

[jrseykid686]

My 2002 EB V8 feels like it is misfiring under moderate and heavy acceleration. Just had it tuned up... all new plugs, new MAF, new IAC, fuel system cleaner, new fuel filter.... and it still feels like misfiring... it only does it with regular gasoline... if i put octane booster or premium she runs like a champ.... but without it it feels like misfiring and a loss of power... any suggestions?
and yes.. it was doing this before the tune up....

 

[fifferaz]

I am having the Same trouble with my 2003 XLT V8. Did you ever figure out how to fix it?

 

[jrseykid686]

i just got my tranny rebuilt, rear axle replaced, differential replaced, and new rear suspension... the "misfire" is actually the autotrac 4x4 turning on... and it is normal if you have an autotrac 4x4 system for it to do so under heavy acceleration, its annoying, but its normal... according to the dealer. I did notice that after the new tranny it doesnt do it as much... i hope this helps, sorry i dont have an answer