Cleaning the IAC. COuldnt find Vaders post.
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Cleaning the IAC. COuldnt find Vaders post.
Hey guys, I read somewhere a while back that Vader had posted a step by step process in cleaning and setting the IAC on the TPI engines. Can someone direct me to it, I can't find it by searching.
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This is from Shoebox 4th gen site, but the 93 is the same as the TPI where it screws into the throttle body.
See this link: http://shbox.com/1/4th_gen_tech2.html#iac_reset
See this link: http://shbox.com/1/4th_gen_tech2.html#iac_reset
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Theres are also better directions for the IAC at www.iroczone.com, very detailed with alot of pics!!!
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It's always good to know what the Tin Man says...
Originally posted by Vader
The "fun" way provided me with a couple of hours of "fun", trying to find the freakkin' spring. After moving a couple other cars and some equipment, it was in the last place I looked....
Cleaning and lightly lubricating the IAC pintle is a good idea. It only takes this much carbon and dirt to completely "kill" the IAC:
Idle Air Control Cleaning
You can remove the IAC and service it. Remove the electrical connector from the IAC. Unscrew the IAC unit from the throttle body.
You can gently rock the pintle back and forth and allow the spring to extend it until it comes apart in your hands. Clean everything with lint-free cloths and a mild solvent. Harsh solvents can affect the insulation of the stepper motor coils. It's generally the dirt and buildup on this worm shaft that causes sluggish IAC operation.
When the worm gear on the pintle shaft is clean and dry, apply one drop of clean light oil to the shaft and work the pintle back into the rack gears of the motor by the same rocking motion. It takes a while to get the pintle back into the worm gears, but you'll get it. It is important to get the pintle fully retracted into the housing so that the pintle is not forced against the gears when reinstalling the IAC unit in the throttle body.
While the IAC is out, clean the air passages in the throttle body. The oriface in the TB where the IAC resides is the seat that the IAC valve closes against, and it can accumulate a lot of carbon, dirt, and debris. The easy way to do this is with carburetor cleaner and a small stiff brush.
When everything is clean and dry, replace the gasket if it is damaged, apply a little anti-seize to the threads, and torque the IAC to the proper specs. (13 ft/lb for '85-'89 , 30 in/lb for 1990-on.) Proceed with setting the TPS and minimum air position.
The "fun" way provided me with a couple of hours of "fun", trying to find the freakkin' spring. After moving a couple other cars and some equipment, it was in the last place I looked....
Cleaning and lightly lubricating the IAC pintle is a good idea. It only takes this much carbon and dirt to completely "kill" the IAC:
Idle Air Control Cleaning
You can remove the IAC and service it. Remove the electrical connector from the IAC. Unscrew the IAC unit from the throttle body.
You can gently rock the pintle back and forth and allow the spring to extend it until it comes apart in your hands. Clean everything with lint-free cloths and a mild solvent. Harsh solvents can affect the insulation of the stepper motor coils. It's generally the dirt and buildup on this worm shaft that causes sluggish IAC operation.
When the worm gear on the pintle shaft is clean and dry, apply one drop of clean light oil to the shaft and work the pintle back into the rack gears of the motor by the same rocking motion. It takes a while to get the pintle back into the worm gears, but you'll get it. It is important to get the pintle fully retracted into the housing so that the pintle is not forced against the gears when reinstalling the IAC unit in the throttle body.
While the IAC is out, clean the air passages in the throttle body. The oriface in the TB where the IAC resides is the seat that the IAC valve closes against, and it can accumulate a lot of carbon, dirt, and debris. The easy way to do this is with carburetor cleaner and a small stiff brush.
When everything is clean and dry, replace the gasket if it is damaged, apply a little anti-seize to the threads, and torque the IAC to the proper specs. (13 ft/lb for '85-'89 , 30 in/lb for 1990-on.) Proceed with setting the TPS and minimum air position.
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