idle drops when a/c turned on ?
Thread Starter
Instructor
Joined: Jun 2006
Posts: 204
Likes: 0
From: MAGNOLIA TX
idle drops when a/c turned on ?
Tuner did a great job on everything but struggled with the idle dropping when the ac is turned on. Car wants to die at traffic light when a/c is on . Turn a/c off.....no problem. 
Anybody ?
Anybody ?
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
YOUR Tuner "DID NOT" do a great gob!
Its an easy fix. Im not a tuner but i saw ENGLANDGREEN ADJUST one table in my PCM that controlled IDLE AIR. The table has TWO columns. One for idle air with AC OFF and the other is for AC ON. IF,,,The values for both colums isnt correct (If they vary significantly) the idle will surge and the car will strugle to idle when the AC is on.
He needs to find that Idle Air Table and make the AC Idle Air the correct value and scue that table properly for the rest of the values!
Bill
Its an easy fix. Im not a tuner but i saw ENGLANDGREEN ADJUST one table in my PCM that controlled IDLE AIR. The table has TWO columns. One for idle air with AC OFF and the other is for AC ON. IF,,,The values for both colums isnt correct (If they vary significantly) the idle will surge and the car will strugle to idle when the AC is on.
He needs to find that Idle Air Table and make the AC Idle Air the correct value and scue that table properly for the rest of the values!
Bill
Racer
Joined: Sep 2009
Posts: 460
Likes: 6
From: Houston
Yep a good tuner will take the time to log STIT from 100% cold to fully warm. Interpolate all other cells it does not hit. The graph for both w/ AC on and ac off will look somewhat like a hockey stick. You also have a PID for the RPM value when it is on. Some like to bump it 50rpm. 
Race Director
Joined: Mar 2007
Posts: 18,308
Likes: 21
From: Marlton. Increasing performance one speeding ticket at a time! NJ
YOUR Tuner "DID NOT" do a great gob!
Its an easy fix. Im not a tuner but i saw ENGLANDGREEN ADJUST one table in my PCM that controlled IDLE AIR. The table has TWO columns. One for idle air with AC OFF and the other is for AC ON. IF,,,The values for both colums isnt correct (If they vary significantly) the idle will surge and the car will strugle to idle when the AC is on.
He needs to find that Idle Air Table and make the AC Idle Air the correct value and scue that table properly for the rest of the values!
Bill
Its an easy fix. Im not a tuner but i saw ENGLANDGREEN ADJUST one table in my PCM that controlled IDLE AIR. The table has TWO columns. One for idle air with AC OFF and the other is for AC ON. IF,,,The values for both colums isnt correct (If they vary significantly) the idle will surge and the car will strugle to idle when the AC is on.
He needs to find that Idle Air Table and make the AC Idle Air the correct value and scue that table properly for the rest of the values!
Bill
Techically, there are 4 rows.
Idle Air
Idle Air (AC on)
Idle Air (In gear)
Idle Air (In gear/AC on)
The tuner needs to hit both rows.
