View Full Version : snap crackle and pop on WOT gear changes


slowstang
09-17-2009, 10:02 PM
My car misfires sometimes when the next gear is selected during WOT and will not accelerate. It's def sounds like the ignition being cut and it will do so without a check engine light. I had the same thing happen at the track but the check engine light was flashing...I aborted the run and the light went off after flashing about 4-5 times.

I'm not using NLS, I know how to drive, and i'm not touching the rev limiter. It comes and goes but has been doing so more often lately. The car runs perfect besides this little mishap. Say I make a pull in 2nd gear and go for 3rd, as soon as the clutch is released for 3rd gear and i'm at WOT it will misfire and not move while i'm on the gas...I let off for a split second, hit the gas again, and it's fine. The 1-2 shift is the more prone for the misfire to appear.

08 SS with 13k miles....new stock replacement plugs(same misfire with stock plugs also) gapped to stock specs, hp tune, k+n drop in.

Is the car possibily seeing overboost somehow inbetween the gear change? The car is tuned for 20psi so I wouldn't think it should be anywhere near overboosting...



Andrew :cssNET:

IsItFast?
09-18-2009, 06:07 AM
try gapping the plugs a little less than stock, you might be blowing out the spark... Or have a coil going bad.

jb09ss
09-18-2009, 06:10 AM
It could have something to do with the tune, but mine does the same thing sometimes ans I am on stock tune. It did it when I was stock, and is still doing it with dp + k&n drop-in. Only does it when I am shifting fast but not using no lift shift. Probably happen only 1% of the time, but it's still strange having that retarded sound and no power at all. Can't help you on what the causes are :confused:

Stamina
09-18-2009, 09:37 AM
This happened to me the other day too (stock/original plugs, Trifecta tune, and K&N Drop-In). Had the temporary flashing CEL and gave three codes (general misfire, misfire on 2, and misfire on 3). I went out and logged with a friend and did more NLSs that evening than I have in the past month :lol:. I noticed I couldn't get it to do it with the ESC Off mode, but I'm still looking into seeing if there's something to that. I did notice though that it tended to do it if I NLS'd a bit slower than normal or a bit earlier in the RPM range than normal.

I'm wondering too if maybe the ECU is detecting clutch slippage after a hard shift or NLS and is letting up so it can catch its footing. Vince was saying the other day that the ECU may have a clutch protection algorithm that detects clutch slippage.

northvibe
09-18-2009, 09:43 AM
you arent NLS'ing but you are AT wot while releasing the clutch? uhhhhhh what?

slowstang
09-18-2009, 12:33 PM
you arent NLS'ing but you are AT wot while releasing the clutch? uhhhhhh what?

I should have said i'm banging gears but not using NLS.

northvibe
09-18-2009, 12:41 PM
I should have said i'm banging gears but not using NLS.

when are you shifting? is it close to redline? sounds like a nls shift.

so you lift off the gas when you shift? because sounds like to me you are miss shifting NLS or you are shifting so fast the car tries to nls.

if you arent trying to nls why dont you just nls?

slowstang
09-18-2009, 12:48 PM
when are you shifting? is it close to redline? sounds like a nls shift.

so you lift off the gas when you shift? because sounds like to me you are miss shifting NLS or you are shifting so fast the car tries to nls.

if you arent trying to nls why dont you just nls?

I lift off the gas when I shift. I don't use nls anymore because my car is tuned wtih an extra 80wtq...I don't want to replace the transmission.

try gapping the plugs a little less than stock, you might be blowing out the spark... Or have a coil going bad.

I'll give that a shot because it def sounds like it's blowing out the spark.

northvibe
09-18-2009, 12:58 PM
I lift off the gas when I shift. I don't use nls anymore because my car is tuned wtih an extra 80wtq...I don't want to replace the transmission.



I'll give that a shot because it def sounds like it's blowing out the spark.

um there are people tuned with over 300whp and nls works fine. by tranny you mean clutch?

Sweetsandman
09-18-2009, 01:16 PM
um there are people tuned with over 300whp and nls works fine. by tranny you mean clutch?

Eh...after seeing what has happened to a few people's transmissions..I'm certainly not NLSing anymore...Especially Ask Maven what happens when you NLS with too much power

northvibe
09-18-2009, 01:35 PM
Eh...after seeing what has happened to a few people's transmissions..I'm certainly not NLSing anymore...Especially Ask Maven what happens when you NLS with too much power

I thought this damn thing was like a rock? haha well my ss only has 150whp so I should be good.

jimssdime
09-18-2009, 01:39 PM
Mine has done it twice so far thought I hit something but it was a backfire. Makes me lol

RYRO14
09-18-2009, 03:27 PM
Yea I'm tuned and when I go into boost and let off the gas it sounds like I did a NLS but I didnt lol what is it? Excess gas being burnt or something worst?

Stamina
09-18-2009, 07:39 PM
Yea I'm tuned and when I go into boost and let off the gas it sounds like I did a NLS but I didnt lol what is it? Excess gas being burnt or something worst?

Yeah, I think it's the excess fuel and then suddenly retarding the spark advance, setting it off.

...I wonder if we can get any flames coming out when that happens... :lol: