yow

I just bought my 06 Vortech V-2 sc'd LS2 C6. Previous owner said tuned to 570/505 and it pulls hard. However, there is hesitation under part throttle between 2-3k rpm that is very noticeable. Under wot is is negligible but I notice it. I had my buddy scan with his HP tuners software but he doesn't know what all he's looking for. We did notice that at wot it drops to 12.9 a/f (seems lean to me) and then runs way low into the 11s and even into the 10s higher in the rpms. I don't know if that is at all a problem, but I'd love to have some input. Should I have it retuned to level out the a/f or what?

In any event, I don't know how to cure the hesitation problem. Is it a misfire? Fuel filter? Air filter? Not sure. The car only has 25k miles with 15 on the sc and never been tracked. At first I thought 'bad gas' but 2500 miles later it still does it (top tier premium only).

I put in a can of Seafoam and am about a quarter way through this tank, hoping it's the injectors and it'll fix it. I'm not too optimistic. Any input?

Thanks in advance!!!

Btw, stock h/c/i only mods are z06 exhaust (full), v-2 sc, and z06 tranny and dif.

DJJONESIVS

Your hesitation could be caused by being overly lean or rich.
Either would or could cause a misfire.

Get someone to retune or take a look at it.
There's an apparent problem , and it would not hurt to double check.

Ryan07

If you have MSD wires, you might want to pull them off and check. I had a misfire at the top end of WOT and when I went to check the plugs, the wires boots fell apart.

Ryan

yow

UPDATE:

I had Jerry Onks (Vettesport.net) in Smyrna tune it. I haven't gotten it back yet but yesterday on the phone he said that he cured the hesitation and tuned it properly. It was rich. I look to get it back today.

He said it went into limp mode (reduced eng power) and he's going to look into how to keep that from happening today. I hope it's just clearing a code or something!

Eric

pmj341

Most S/C cars run 10.5-11.9 AFR at WOT
I'm NA and I run 12.3 at WOT, cruising it's 14.7 to 15.1
there are several guy's on here that can help you with the tune.
if the tuner you took it to went leaner than 11.9 it's possible he did engine damage. S/C cars need the fuel

06z06_427

I would look at plugs and wires and if it's not that then check tune. Sc cars need a tighter plug gap but that usually presents issues on the top end vs mid range.

yow

Fyi I think we got it fixed. It seems that the burst knock sensor was retarding timing. Jerry Onks of vettesport tuned it out. If it comes back ill update. Thanks guys. I hope this thread helps someone in the future.

White_06_A6_C6

your speaking two different possibilities. did your tuner say you had burst knock indicated? or that your knock sensors were going off and pulling timing? two totally different situations.

burst knock on a car w/ all Z06 OEM exhaust is very odd sounding. might ask for clarification for exactly what type of knock was indicated.