dyno tune now car wont idle

[minytrker]

I co-worker had his car, 2002 corvette with heads, cam, and headers dyno tuned by a very known tuner. He drove the car several hundred miles to his shop. It ran fine on the dyno, and started and idled with no problems. Now a couple hundred miles later the car dies when you start it. If you keep it running by giving it gas it will idle after awhile. It does this evertime you start the car no matter if the car is cold or hot. Once its running it drives good but it will also die once you come up to a light after driving at speed. It did none of this the day it was tuned or for the couple hundred mile drive home, it even got 30mpg. Any ideas?

[bink]

Needs to have the idle air adjusted- RAF. It's out of range of the LT/ST idle air.

[TAQuickness]

I would start with Bink's suggestion. Does your compadre have a copy of live and a WB? If so, once you get the B4307 (RAF) inline, take a look at the open loop fueling and the BEN's in the idle range.

[Bruce Melton]

Needs to have the idle air adjusted- RAF. It's out of range of the LT/ST idle air.

Bink,
This topic is so common but would you venture a specific table and value?
Once the RAFIG and RAFPN is logged what to change to what or % or?
Thanks,
Bruce

[minytrker]

I would start with Bink's suggestion. Does your compadre have a copy of live and a WB? If so, once you get the B4307 (RAF) inline, take a look at the open loop fueling and the BEN's in the idle range.


I have the workshop version and a wb but its installed in my car currently. I havent had a chance to look at his car yet. Thats why I was posting on here. I figured someone on here would know whats wrong without seeing it. How did the car run fine for the first day?

[TAQuickness]

There are several variables to consider here, but to keep it short, it takes a while for the idle trims to relearn, and the PCM only initiates idle learn under certain conditions.

You will want to create a map emulating the B4307 table, log RAFIG and or RAFPN, then paste and add the values.

[minytrker]

How long do I need to log this for, just long enough to see what the airflow is? Do I need to do with the car cold and warm?

[Bruce Melton]

How long do I need to log this for, just long enough to see what the airflow is? Do I need to do with the car cold and warm?

Looks like temp related so let's assume a warmup:


http://home.new.rr.com/meltn/idle.jpg

Then?

[Doc]

That 4307 table you posted has zero air for P/N? At all temp ranges?

[Bruce Melton]

That 4307 table you posted has zero air for P/N? At all temp ranges?

Stock 02 Z06 table for example.

[bink]

Cold warm up at idle (AC Off) - RAFIG. There are a bunch of factors that may effect RAFIG depending on your cam and idle speeds.

[minytrker]

I see in the screen shot you have a 02 Z06 tune. Do you happen to have the stock tune. I dont have the stock tune for my car and would like to have a stock tune for it. I downloaded one off the net but it was a differnt OS. My OS is 12593358.

[minytrker]

Cold warm up at idle (AC Off) - RAFIG. There are a bunch of factors that may effect RAFIG depending on your cam and idle speeds.

Its a small cam 232/236, .575/.578. I havent got a chance to scan the car yet but going off the tach it idles at 800 or close to it once you get it to idle.

[wait4me]

On manual cars it is like that because the computer always assumes the vehicle is in drive. That is why i it has zeros.

One thing for everyone to watch out for it the table Units, on Bruce's Picture above, The units are in Grams/sec. So the numbers look much larger than the other unit scaling.

Just make sure your units match before you try to copy and paste tables.

[Bruce Melton]

On manual cars it is like that because the computer always assumes the vehicle is in drive. That is why i it has zeros.

One thing for everyone to watch out for it the table Units, on Bruce's Picture above, The units are in Grams/sec. So the numbers look much larger than the other unit scaling.

Just make sure your units match before you try to copy and paste tables.

Good point!

http://home.new.rr.com/meltn/b4307lb%20(Medium).jpg

[bink]

On manual cars it is like that because the computer always assumes the vehicle is in drive. That is why i it has zeros.

One thing for everyone to watch out for it the table Units, on Bruce's Picture above, The units are in Grams/sec. So the numbers look much larger than the other unit scaling.

Just make sure your units match before you try to copy and paste tables.
Hey Jess!

That's why I always try to leave everything in metric - except MPH.;)

:cheers:
joel

[TAQuickness]

Deg C still doesn't work well for me...


You'll want to log a complete cold start - ambeint to 3-5 minutes after full operating temperature.