Thread: Launch control cutting my rpm randomly

My pin #46 had 12v running to it after letting the car sit for 16 hours.

I do not have a functioning neutral switch installed.

I will email you a .tcl of the problem and the related .tcd

In that case, "set launch" won't work, so just disable it and set your launch limit (LAUNCH RPM) with NismotronicSA. With no neutral switch, the ECU thinks you're in gear all the time and will always enable launch control. To disable launch control, set LAUNCH MAX SPEED to 0.

With the latest version, you can now use a separate switch to enable launch control.

Pin #46 is the one that must be 12V all the time, even with the ignition key off.

Dave

"With the latest version, you can now use a separate switch to enable launch control."

Woah, must have missed that, will install a switch asap! I have been away from my car now but i will report this weekend if I get it solved with this new info! Great opportunity to install another switch for fuel map-switching, this is gonna be awesome!

EDIT: Forgot to say that my ECU's circuit board was repaired when I installed the NEMU. I had severe corrosion on the corners, previous owner probably let moisture get in from leaving the t-tops off during rain It looked similar to this:

Board was cleaned off, and new protective lacquer applied. It wasn't malfunctioning before, so I was lucky it was salvageable! Don't think it has anything to do with my problem, since D-Unit121's problem is identical to mine

Here's a wiring diagram for using a NEMU ADC input as a switch input. With the diode, it can be a 12V switch, like the E-brake switch.

@Dala

I figured out why my car was having the weird set launch RPM after cold starts.

My TPS was reading 0.47v when cold and the ECU was recognizing this as 2% throttle.

During my cars warm up cycle the TPS voltage gradually drops.

After the car warms up, my TPS goes to 0.37v and the ECU recognizes this as 0% throttle.

When the car is started cold, the set launch RPM is getting messed up by the ECU seeing 2% throttle.

Im not sure how to fix this, maybe its mechanically adjusted wrong? Ive always struggled with dialing in the TPS sensor with my NEMU for this reason. When i adjust it cold, i get improper voltages when the engine is warm, however when i adjust the TPS when the engine is warm, i get the issue that i have now.

before i figured this out, i had replaced my engine harness. wiring is now not an issue.

Hey, I thought about that aswell! 2% throttle for me too, haven't gotten around to adjusting it. The car still is hard to start if it sits for longer than 12hours. 1500rpm first start etc..

One other thing, I don't have the ACC valve hooked up! I noticed it when i set my idle speed last weekend (1100rpm->900rpm). If I connect my AAC valve, the idle starts to bounce between 2000-2600rpm. Guess I should just leave it disconnected since it idles perfectly without it? Or has this something to do with the hard cold starts?

Will report back after I adjust the TPS and think more about the ACC valve.

our engines really rely on the aac to idle peoperly. when the engine is warm it should idls around 50% duty.

your engine should run at a higher rpm and richer on cold start conditions.
all of the cold start conditions are adjustable via your ecu.

I've now got the AAC hooked up, and configured properly. The cold start hasn't been an issue, but the weather has gotten so hot here, so I don't know if it is temporary.

To summarize:
-Engine starts perfectly.
-Sometimes, launch control activates improperly at 1500rpm when starting, not a problem, but sounds strange, since the car wants to cold start idle at 1600rpm for the first seconds. Launch control returns to normal 3000rpm after a few seconds (about 20).

It was all in the settings..