Idle Air Control Valve (ISV) Compatibility? Are the IAC/ISV motors the same?

[suprunner]

Hi all,


My 1990 7m has a bad Idle Air Control Valve/Idle Speed Control Valve (IACV/ISCV). Symptoms include fluttering/weak idle at operating temp, not wanting to stay running on cold starts, and the plunger wouldn't move when I did the TSRM check by supplying power to the contacts... http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=FI&P=107

When it's warm, I have to hold the accelerator down while at a stop.

My question deals with the compatibility of the motor unit of the valve. . . There are a few different Idle valves for sale on ebay, and I'm wondering if they'll work. The part number on my valve is: Denso 22270-42030... Would one from a 92/93 Lexus/Camry/ES300 3.0L work? Do the plungers operate differently?

http://www.ebay.com/itm/321190265902?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

Do I just need to buck-up and buy a new one? $350....

Thank you for the help,


Greg

 

[f00g00]

I don't believe it is interchangable with any other engines. Get one from a self service junkyard for cheap.

 

[jetjock]

Indeed, the EPC shows it's only a 7M thing:

http://www.cygnusx1.net/Supra/Library/EPC/291420/part.aspx?S=22270

That said as long as the motor is good the assy is usually repairable. Therefore make sure you did the test correctly. Maybe ohm the windings before condemning the motor. Do you hear it click just after shutting the engine off? All I'm saying is be sure because some of your symptoms don't indicate a faulty ISCV.

 

[egesledder]

Also, make sure your TPS is working correctly. I recently had a similar issue and a new TPS tuned properly solved it. The old TPS wouldn't return completely when the throttle was closed and therefore wasn't giving an IDL signal to the ECU. This problem didn't throw any codes for me either, so its something to at least check.

 

[jetjock]

^ Although it doesn't get set into memory that condition generates a code 51.

 

[suprunner]

Also, make sure your TPS is working correctly. I recently had a similar issue and a new TPS tuned properly solved it. The old TPS wouldn't return completely when the throttle was closed and therefore wasn't giving an IDL signal to the ECU. This problem didn't throw any codes for me either, so its something to at least check.

That is where I first turned to. The TPS has been adjusted with the throttle body. I checked the resistance of the ISV, and I got 22.1 across the board. Now I need to rig something up to accurately check the function again. The last attempt had the plunger not moving in or out. It made a motion that seemed like something was stuck. . .

 

[suprunner]

Indeed, the EPC shows it's only a 7M thing:

http://www.cygnusx1.net/Supra/Library/EPC/291420/part.aspx?S=22270

That said as long as the motor is good the assy is usually repairable. Therefore make sure you did the test correctly. Maybe ohm the windings before condemning the motor. Do you hear it click just after shutting the engine off? All I'm saying is be sure because some of your symptoms don't indicate a faulty ISCV.

I never have heard the click when shutting the motor off. I DO however hear a rapid three/four click sequence whenever I change the position of the gas pedal while driving.

 

[suprunner]

Indeed, the EPC shows it's only a 7M thing:

http://www.cygnusx1.net/Supra/Library/EPC/291420/part.aspx?S=22270

That said as long as the motor is good the assy is usually repairable. . .

Those numbers aren't found on the actual motor assembly. They are printed on the portion that the motor assy screws on to. Which makes me hope that the motors could be interchangeable, but the lower portion is specific to different motors....