Z06Vette.com - Corvette Z06 Forum

ZO6 Bryan · 12-16-2007, 07:53 PM

I have an 02 ZO6 with LG pro headers and a 232/236 duration cam that I have tuned and it runs well and has good drivability except for one problem. It will surge and try to die right after starting it when already warmed up. Cold start is no problem. And it only does this for about the first 20 sec. after a warm start then it is fine. I have already SD tuned it and re-enabled the MAF. The LTFT's are very good at +/-4. It idles at 25 deg advance. Any suggestion from the experiened tuners. I can e-mail a .hpt file and a log that demonstrates the problem to anyone willing to take a look.

ZO6 Bryan · 12-18-2007, 07:25 AM

Bump
Can anyone help with this. What's going on in the first 20-30 sec after start-up? I've already lowered the afterstart enrichment and tried several other things. Done the VE tuning already. Is it something to do with the idle air routine coming online takes that amount of time or is it something to do with fueling. Like it takes 1/2 a minute to switch to MAF from SD right after start-up?

**FRC Tom** · 12-18-2007, 10:24 AM

Send me your file and I will do my best to fix the problem.
ttt@c5frc.com

232/236 is what I have been running for years, first with a s/c and now with TTs.

JBsZ06 · 12-18-2007, 01:41 PM

thats awesome Tom..

What a great offer.

Let us know how it works out.

Happy holidays.

JB

ZO6 Bryan · 12-18-2007, 02:02 PM

Quote:

Originally Posted by FRC Tom

Send me your file and I will do my best to fix the problem.
ttt@c5frc.com

232/236 is what I have been running for years, first with a s/c and now with TTs.

Thanks for the help. I'll send it tonight from my laptop when I get home

Eddie 70 · 12-24-2007, 09:13 AM

Just curious as to how this has turned out. My sons camaro does this and it has a relatively small cam. We are still playing with the tune.

ZO6 Bryan · 12-24-2007, 10:14 AM

Quote:

Originally Posted by Eddie 70

Just curious as to how this has turned out. My sons camaro does this and it has a relatively small cam. We are still playing with the tune.

FRC Tom has my file and I'm waiting to hear back from him. With the holidays I figure he has more important things right now. Didn't want to rush him.

ZO6 Bryan · 01-07-2008, 07:05 PM

I have to give thanks to FRC Tom for his help. After some changes he made to my HPT file and a little tweaking I did after that, the car runs great with no surging and great drivability for a cam of that size.

**FRC Tom** · 01-08-2008, 08:11 AM

Quote:

Originally Posted by ZO6 Bryan

I have to give thanks to FRC Tom for his help. After some changes he made to my HPT file and a little tweaking I did after that, the car runs great with no surging and great drivability for a cam of that size.

Very welcome Bryan.
Yes I was tied up and i do poligize for not getn the file back to you sooner.
Any other probs jus let me know.............................
I try not 2 turn wrenches ne more, I am a PC tuner...

merry, merry and a happy.

**RC45** · 01-27-2008, 01:03 PM

So what was the cause and then the solution?

It is interesting to read about these issues - but it would be even more interesting to hear the technical discusison surrounding the solutions

**FRC Tom** · 01-28-2008, 12:41 PM

Quote:

Originally Posted by RC45

So what was the cause and then the solution?

It is interesting to read about these issues - but it would be even more interesting to hear the technical discusison surrounding the solutions

There are a number of idle airflow tables I work with.
Base airflow and Throttle Follower in nuetral and gear.
Depending on the problem I either increase or decrease the numbers.
The follower tables dictate how fast the throttle closes when you get off the pedal.
There is also seperate spark advanced tables for idle that I change.
Then the VE table from 1200 rpms on down I will normally decrease by 10-15%.

**RC45** · 01-30-2008, 02:28 PM

Thanks - very informative.