Rough idle when a/c is turned off

Indigonova · 06-04-2021, 03:53 PM

I have an 87 7mge starts and idles fine, but when I turn off the A/C the rpms drop and it almost stalls. If it were the other way around I would understand, anyone else ever experience this issue?

Bru · 08-16-2021, 01:25 AM

When the AC is engaged the computer bumps up the rpm's and when it shuts off it returns it back to idle. Try cleaning the idle speed control valve and be sure that the rubber check valve inside is pointing in the right direction on a GTE and not damaged. The motor is a stepper type which means it only moves slightly when each coil section is energized manually. There are 6 contacts. The order that they are energized determines the direction that the cone end moves to control the flow of air. Here is a link to the online supra manual for that testing.

http://cygnusx1.net/Supra/Library/TS...spx?S=FI&P=106

06-04-2021, 03:53 PM	#1
Indigonova Stock Join Date: Jun 2021 Location: Hillsdale Ontario Posts: 1	Rough idle when a/c is turned off I have an 87 7mge starts and idles fine, but when I turn off the A/C the rpms drop and it almost stalls. If it were the other way around I would understand, anyone else ever experience this issue?

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08-16-2021, 01:25 AM	#2
Bru Bone Stock w Upgrades ;-) Join Date: Apr 2010 Location: Tampa Bay Posts: 210	When the AC is engaged the computer bumps up the rpm's and when it shuts off it returns it back to idle. Try cleaning the idle speed control valve and be sure that the rubber check valve inside is pointing in the right direction on a GTE and not damaged. The motor is a stepper type which means it only moves slightly when each coil section is energized manually. There are 6 contacts. The order that they are energized determines the direction that the cone end moves to control the flow of air. Here is a link to the online supra manual for that testing. http://cygnusx1.net/Supra/Library/TS...spx?S=FI&P=106