High Rolling Idle

[mattmonaro]

How do i reduce the high rolling idle on a early VT LS1 auto with cam and std stall speed. There is no Rolling Idle table like the later models.

[mowton]

How do i reduce the high rolling idle on a early VT LS1 auto with cam and std stall speed. There is no Rolling Idle table like the later models.

Without any additional info, reduce the RAF (min idle air) by say .5 to ,75 g/sec at the operating temp and above. Sounds like cruise control....What is the timing when this event is happening. A Log and tune posting would certainly help.

Ed M

[SSUte01]

Cracker is the main airflow adder variable with vehicle speed. You will also have Follower adding as a function of TPS. Log the various airflow PIDs to see what's adding what. Timing also plays a function to engine speed particularly if there is a large delta between your base idle and main table on Gen 3 with your type of setup. You need to show a log with dynamic cylinder air, rpm, fps, vehicle speed, STIT (if the log shows stationary), advance, cracker airflow, follower airflow, AC airflow etc. But as per above the RAF forms the base to which other adders modify.

[mattmonaro]

Ive since zeroed throttle cracker, set enable to 412 kph and zeroed throttle follower delay and it made it alot better but feels like ive lost some throttle response.
Base idle airflow is set to best idle in park and drive.
Its soon as the vehicle moves is when it idles up.
Do i need to change Adaptive Idle Airflow figures ?

[mowton]

You need to post the tune file....

Ed M

[mattmonaro]

Here it is sorry

[SSUte01]

The VT drive log has none of the airflow PIDs logged unless I missed something so I can't ascertain anything. Is it a standard throttle body? The RAF looks very high though.

[mattmonaro]

Yeh i havent logged them yet, being stubborn.
STD throttle body, unknown cam specs

[mattmonaro]

Some idle airflow

[mattmonaro]

All Idle airflow PIDs

[mowton]

Why is your IAT temp pinned at 158 degrees? Assuming you do not have a MAF sensor (that appears inop as well) as you have the 1 bar custom OS applied. Did you relocate the IAT sensor?

Ed M

[mattmonaro]

It is a mafless SD tune.
Air cleaner is still sucking some air from hot engine bay.
Was a 31 degree celcius day today aswell.
Owner is going to make changes to air cleaner. Air intake temp sensor is still in airbox as per factory.
I normally see 35 degrees celcius air intake temps on a proper intake setup

[mowton]

It is a mafless SD tune.
Air cleaner is still sucking some air from hot engine bay.
Was a 31 degree celcius day today aswell.
Owner is going to make changes to air cleaner. Air intake temp sensor is still in airbox as per factory.
I normally see 35 degrees celcius air intake temps on a proper intake setup

Have to get IAT straightened out first

Ed M

[mattmonaro]

Yeh, it is the highest temp ive seen on a naturally aspirated setup

[Road]

You are running on you main spark table at idle sometimes that will give a cruise control feel might try lowering your max speed down to <1mph

[mattmonaro]

Yeh true, but the main spark table and idle spark tables are the same where it counts

[mowton]

You are running on you main spark table at idle sometimes that will give a cruise control feel might try lowering your max speed down to <1mph

It is more the desired airflow...bounces from 7 to 14 g/sec. It appears you are bouncing between P/N and in gear idle modes. Watch the ftc,,,17 and 19. Are you doing that on purpose? is your p/n sensor at fault?

Both FTC 17 and 19 need tuning to get LTIT down closer to 0%

Ed M

[mattmonaro]

It is more the desired airflow...bounces from 7 to 14 g/sec. It appears you are bouncing between P/N and in gear idle modes. Watch the ftc,,,17 and 19. Are you doing that on purpose? is your p/n sensor at fault?

Both FTC 17 and 19 need tuning to get LTIT down closer to 0%

Ed M

Definately not not that on purpose lol
Ive never had a car be so erratic as this.
FTCs are in the ballpark i thought but i dont know why the desired airflow is fluctuating so much .
IDLE DESIRED AIRFLOW is 7.4 and IDLE BASE P/N AIRFLOW is 11.4 and the IDLE ADAPT (STIT) is -4.3. I dont know why the desired airflow is at 7.4 ??
Difference between P/N AIRFLOW and GEAR AIRFLOW is 1.3 g/sec which is ok i thought.

[mowton]

Definately not not that on purpose lol
Ive never had a car be so erratic as this.
FTCs are in the ballpark i thought but i dont know why the desired airflow is fluctuating so much .
IDLE DESIRED AIRFLOW is 7.4 and IDLE BASE P/N AIRFLOW is 11.4 and the IDLE ADAPT (STIT) is -4.3. I dont know why the desired airflow is at 7.4 ??
Difference between P/N AIRFLOW and GEAR AIRFLOW is 1.3 g/sec which is ok i thought.

My point is you are bouncing between FTC 17 (P/N idle) and 19 (In Gear).....

Ed M

[mattmonaro]

My point is you are bouncing between FTC 17 (P/N idle) and 19 (In Gear).....

Ed M

yeh ok. Im not sure how to stabilize that .