Coast idle too high only with ac on

I have a '99 s10 with a 5.3 swap. It's running off a 2002 silverado tune file and a 411 PCM. And a cable throttle.

I've figured everything out and it runs great but I added a/c. Didn't really change anything tuning wise, but now it cruises with the a/c on only.
Like going through a shopping center it doesn't need my foot on the throttle at all. I can shut the a/c off and it drives normal.

Everything is wired 100% like the factory had it.

Can anyone guide me to fixing this problem?

Thanks.
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Just as a test, go to ENGINE>SPARK>ADVANCE>GENERAL>AC BUMP TORQUE SPARK.. Currently it is set to ENABLED. As a test, change it to DISABLED, burn it, and then drive it to see if this condition changes, or goes away.

You also have not told us what you are running for a cooling fan. Did you swap to electric fans? Or, still running the thermal clutch fan?

Quote:

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Originally Posted by 1364838952

Just as a test, go to ENGINE>SPARK>ADVANCE>GENERAL>AC BUMP TORQUE SPARK.. Currently it is set to ENABLED. As a test, change it to DISABLED, burn it, and then drive it to see if this condition changes, or goes away.

You also have not told us what you are running for a cooling fan. Did you swap to electric fans? Or, still running the thermal clutch fan?

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Electric fans. Not sure how that would matter because it doesn't idle different with the fans on and ac off. They're controlled by the pcm.

Probable have to mess with the airflow settings for ac ... sounds like too much airflow is being used causing the throttle to stay open/idle hang

So thats the adaptive idle airflow --->> AC offset min/in gear, and AC offset Max/in gear?
I'm not sure what table to adjust.

idle - airflow - adaptive idle section - just try zeroing out the ac airflow and see how it goes - can you post a log of just idle no ac for a min or 2 and then with ac on logging iac counts and idle airflow pids

I just tried a bunch of crap that didn't work. The only thing that helped was the a/c stuff under engine torque management. Zero'd out works, but it affects it when not in gear.

This is a scan of it coasting at the end, it's moving itself at 11 mph then a/c request shuts off and it goes down to almost a stop. I know it only has IAC position but I got tired of screwing with it.

Attachment 81844
Attachment 81845

Quote:

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Originally Posted by 1364838952

Just as a test, go to ENGINE>SPARK>ADVANCE>GENERAL>AC BUMP TORQUE SPARK.. Currently it is set to ENABLED. As a test, change it to DISABLED, burn it, and then drive it to see if this condition changes, or goes away.

You also have not told us what you are running for a cooling fan. Did you swap to electric fans? Or, still running the thermal clutch fan?

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Nope

Quote:

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Originally Posted by TCSS07

idle - airflow - adaptive idle section - just try zeroing out the ac airflow and see how it goes - can you post a log of just idle no ac for a min or 2 and then with ac on logging iac counts and idle airflow pids

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Nope

wont let me open the log - says incorrect header

could you repost the current file

Quote:

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Originally Posted by TCSS07

wont let me open the log - says incorrect header

could you repost the current file

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Well. Nope. I transfered it from my laptop to desktop and get the same message on the desktop. Done. F it let it idle high. Hptuners help forum for the mf'ing win yet again.

It's under Engine -> Torque Model -> Loss -> A/C Compressor. And with my factory base tune that doesn't reference the pressure sensor -->> vs IAT.

This approximates a/c pressure by referencing the intake air temp sensor. A/C pressure determines load or torque needed to drive the compressor. If a compressor other than the stock one is used this may need to be modified.

All the airflow tables, idle tables, etc, "say" (when you mouse over them) that they are only used when the compressor turns on or off. Not while driving and moving.

If you can cruise through a shopping center with a cruise control effect that goes away when the a/c is shut off, this is the table you need to modify.

what kind of a/c compressor is it? aftermarket Sanden style or original to LS style engines. LS style engine have a flapper setup to compress and the sanden is a piston style witch take much less power to turn, in the torque management table there is a file that is meant to add airflow against a/c pressure ( PSI ) that table has to be zeroed out....take the a/c tables from a 2002 express van calibration and that will correct it. if its a piston style compressor

Quote:

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Originally Posted by capss9c1

what kind of a/c compressor is it? aftermarket Sanden style or original to LS style engines. LS style engine have a flapper setup to compress and the sanden is a piston style witch take much less power to turn, in the torque management table there is a file that is meant to add airflow against a/c pressure ( PSI ) that table has to be zeroed out....take the a/c tables from a 2002 express van calibration and that will correct it. if its a piston style compressor

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No, in the lastest update it's under torque model. Theres a PSI table (which is zero'd in my stock calibration) and there is a IAT table, which takes intake air temperature and approximates PSI from it.
LS compressors have pistons it's just a variable displacement that doesn't need to cycle. It has a variable angle swash plate.