2006 Corvette will not catch idle, at wits end

[TheDastardlyDuo]

I am working on a 2006 Corvette GT2 spec'd car, so it's basically carbon fiber and roll bars. It's running a 6L LSx block with LS3 heads and C5R cam shaft from GM (25x/26x durations, <.610lift). It also runs on 110 leaded fuel so narrow bands are out of the question.

The company in which built this car has built another one using a 2002 C5 PCM, and that one works great. This car however is using a 2006 PCM, and I'm pulling my hair out. I can get it to idle at 950rpm, it goes cleanly through 8000rpm, but as soon as you let your foot off the gas pedal, the car will not catch the idle and will die. This is not something that happening with their other car.

I have been tuning for 8+years with HPTuners, and log over 40hrs a week on a chasis dyno all year, not to mention engine dyno's. I have over 30gigs of HPTuners files and data logs. This is the first time I have ever had this problem. I have tried adding and subtracted air via "airflow final minium", I have added and taken away spark from 6-30 degrees, and my AFR via the wide band is between 13.3-14.0.

I am including the data log and tune file. Look at time stamp 2min 34sec.

[Google]

from what i can see the pcm is staying in decel (fuel trim cell 38) untill 285 rpm then it switches to cell 33 and can't recover. have you tried adjusting your map/rpm boundarys yet?

[TheDastardlyDuo]

Point me to the correct tables and I'll look into doing it. Have never had to before. At this point I'd be happy with an Idle hang, as long as this car won't die.

[TheDastardlyDuo]

I also just set the high speed enable to 2, and the disable to 1, no change.

[TheDastardlyDuo]

50 files later, I figured it out.

[Google]

if the computer is in decel mode fuel trim cell (38) under idle rpm I don't think it will use adaptive idle corrections so you will need to be in fuel trim cell 37 (idle) when you reach your idle rpm.

[IDRIVEAG8GT]

Just put a floor on the Minimum TPS. Like 20% or whatever and tune from there. Unless you really got it good.

[Google]

Just put a floor on the Minimum TPS. Like 20% or whatever and tune from there. Unless you really got it good.

you could but imho it is better to have the boundaries in the right places then your not raping the tables and being put on the sex offenders list for life..

[DSteck]

50 files later, I figured it out.

What'd you find?

[IDRIVEAG8GT]

you could but imho it is better to have the boundaries in the right places then your not raping the tables and being put on the sex offenders list for life..

No no, there's another table that just tells the TPS not to go below X percentage. I would never have anyone do a stupid ass PE Rapage tune! @#$%^&*

[TheDastardlyDuo]

I found one of the issues with working with an older Beta version, I installed the newest one (which I downloaded two weeks ago, but been too lazy to install), and was able to get the car to do what I wanted it to do.

Basically when I was trying to set the high rpm disable to 2, and the high rpm re enable to 1, it wouldn't save, saying that the boundry's were outside the array. The newer beta version didn't have that problem. Once I did that, I had to add a little fuel to the MAF table and it was good to go. 8hrs of trying to get this damn car to idle, and just loading different software fixed it in 2 min.

I think I'm going to throw a motor together using this cam in the future, nothing under 4000rpm, but after that it's like a shot of nitrous.

[IDRIVEAG8GT]

I think I'm going to throw a motor together using this cam in the future, nothing under 4000rpm, but after that it's like a shot of nitrous.

Lmfao. I like how those cams sound at idle..... But I want one that'll build power down low at like 2000 up to 7000 and idle like a pissed off Wolverine. I thought I found what I wanted in MTI, but nah, they don't sound like I want. Ever tuned anything with a cam like that?

[TheDastardlyDuo]

Lmfao. I like how those cams sound at idle..... But I want one that'll build power down low at like 2000 up to 7000 and idle like a pissed off Wolverine. I thought I found what I wanted in MTI, but nah, they don't sound like I want. Ever tuned anything with a cam like that?

The only cams I've tuned with a powerband between 2000-7000rpm are in LS7's.

[IDRIVEAG8GT]

Hmmm.... Damn.

[torrese1]

i have this same problem but this vett seams to have a hard time starting also when it cold in open loop once it goes in to cloesd loop it seams to do better on the start up any advise on this guys?????????

[torrese1]

hey idriveag8gt where is the tps tab that you said to set to 20% under i dont want to move the wrong one.

[Jabbott]

hey, how much when you retune that car to only put about 6 degrees of timing in it and put the say a 2.00 all the way across the PE table.

Tell Robert that someone from Richmond Va requested that.
Thanks
Justin