Limp mode when launching at the strip

[Krinkov]

I've had a problem at the track a both times I went and wonder if anybody else has experienced this? When I launch the car it either is in limp mode, or somehow is in second gear, (or maybe limp mode puts you in second gear?). Since it never has happened on the street I can imagine it must be caused by one of three variables...things I wouldn't normally do on the street.

The burn out - I know if you hit the rev limiter it can cause limp mode...but I'm careful to not go over 4500rpm - maybe five grand. I believe my stock limiter is around 6000rpm.

Excessive key cycles - In an effort to keep it cool prior to the pass, I start and stop the engine repeatedly working my way up the staging lanes.

Not at full temp before running it hard - I try to keep it cool...guessing it was around 150-170* when this has happened.

Help me fix it. I plan to go racing this weekend. Twelves here I come!!!

[done]

When you say it is in second gear, do you mean it seems to start in second, downshifts to first and then shifts up normally as you go down the strip?

I have had this happen and I think it is related to holding the RPM's at a high level for too long at the tree.

[Krinkov]

I mean it seems to start and stay in second gear, or just has no power in first gear. It just fell on it's nose out of the hole and about half way through whatever gear it's in it comes back to life and starts pulling hard. At the time it didn't occur to me that it might be in a higher ger so I didn't pay attention to how fast it was going before it shifted. Didn't count gear changes either.

I did brake torque it but not much, and not for very long...maybe after the second yellow lit.

[done]

I mean it seems to start and stay in second gear, or just has no power in first gear. It just fell on it's nose out of the hole and about half way through whatever gear it's in it comes back to life and starts pulling hard. At the time it didn't occur to me that it might be in a higher ger so I didn't pay attention to how fast it was going before it shifted. Didn't count gear changes either.

I did brake torque it but not much, and not for very long...maybe after the second yellow lit.

I also found that resetting the transmission adaptives before each race session keep it from happening.

[robsrt]

Bring your rev limiter down to 6650. The TCM has a built in rev limiter of 6700. Once the TCM sees that rpm it goes into limp mode. I've had this issue as well as many others. Once I've done that, I haven't had any issues.

[Krinkov]

The already had the rev limiter at 6000rpm according to my Diablo. Confused.

On another note, I appreciate you taking the time to chime in on my many noob questions.

[renman]

How long are you holding your RPMs when you launch. Ive read on this site that the PCM will pull timing if your higher RPMs are held for 2 yellows or longer.

[aslcharger08]

With a 3200 stall you don't need to brake stall.....it defeats the purpose of the converter, these aren't standard transmissions. All you need to do is line up at the light and stomp the gas when the light goes.

On your burnouts are you leaving it in D or are you in autostick? You should be in autostick so you can control which gear you want so the car doesn't think your just spinning and it needs to upshift to grab traction.

Another thing you can try is going into your diablo tuner and put dyno mode on, this will cut out the abs and traction control. I always did this at the track and never went into limp mode at the launch.

[aslcharger08]

One other thing, if you like the car to upshift for you when your at the light put it in autostick for 1st gear and then just take off. It will then upshift on it's own but it shouldn't go right into 2nd gear short of your WOT peak shift point.

[robsrt]

The already had the rev limiter at 6000rpm according to my Diablo. Confused.

On another note, I appreciate you taking the time to chime in on my many noob questions.

Double check your trans fluid. The Nag1 is very sensitive to proper fluid levels. I'd have the dealer double check just to be sure.

[done]

Double check your trans fluid. The Nag1 is very sensitive to proper fluid levels. I'd have the dealer double check just to be sure.

Rob, he is not going into limp mode. What is happening, the car launches in second gear, shifts down to firat and then goes normally. I have had this happen on several occasions. I minimize the occurences by resetting trans adaptives when I get to the track and starting in first-autostick.

[whitehemi]

My car did this aswell in auto stick only. Now I do the burn out in auto stick then put in drive to launch and race. I haven't had it launch in second gear since.

[2006SilverRT]

^^^^This. My car does the same thing if in autostick....it will shift to 2nd immediately. I just do the burnout in autostick and kick it back into drive to race. No issues yet.

[Illinois Chaos]

For some reason it's ok to start in 2nd with these Nag1's. It states that in the manual. I have seen it happen to mine after a burnout. It just selects 2nd afterwards even though I finished in 3rd. I force it to 1st by pushing on auto stick until it drops down. I think that if your car is shifting into second right away on launch it's because of driving it on the street and is a learned behavior. After a couple or 3 wot runs it should stretch out first to the redline and be fine after relearning a new style of driving.(reset adaptives, like Done mentioned will solve the issue also) I only use auto stick and it shifts perfectly everytime down. The car only sees 1/4 mile passes though and has adapted to wot runs only.