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A/C Update Kit
Aux. Turbo Pump
Control Arms
Crank Scraper
Cross Member
Idle Valve Test
Intake Manifold
Fuel Rail
Fuel Rail Gauge
Harness Repair
Oil Pan
Reflector Housing
Rod Bearings
Sway Bar
Sport Seats
Steering Rack
Struts (Koni)
Turbo X-Over Pipe
Vacuum Replacement

Idle Control Valve Testing

 

NOTE: The idle control valve can be called many things including:

If your idle air control valve is not working properly, it can lead to poor, surging, idle. The ICV is expensive ($80 rebuilt or $150+ new), so you don't just want to replace it unless you know for certain it is bad. The following test was done with my Power Probe, which is one of the best tools I own. I highly suggest you buy one if you plan on doing any electrical diagnostics.

One way of testing the ICV is given at Clark's Garage. This is a good test, especially if the ICV is still connected. However, if you suspect problems with the ICV, and you disconnect it, you might as well run my test to check for certain. The Clark's Garage procedure is as follows:

Clamp line from Idle Stabilizer / Auxiliary Air Valve to the intake manifold to see if idle stabilizes. If it does remove the Idle Stabilizer / Auxiliary Air Valve, clean it with Carburetor and Choke cleaner, reinstall and check operation. If the surging idle persists, replace the Idle Stabilizer / Auxiliary Air Valve.

 

To test the actual workings of the ICV, use the following method:

Hook up the power probe to a 12v power source such as your car body. Attach a alligator clamp jumper to the ground on the Power Probe (yellow) and another jumper to the needle of the power probe (red). Give the inside of the ICV a good cleaning. I sprayed carburetor cleaner first for cleaning, then WD-40 for lubrication.

There are three terminals on the ICV. The center terminal is positive, so attach the positive lead to this terminal. The two outside terminals are ground. The ICV works by swapping ground rather than swapping positive electricity.

Attach the positive jumper to the middle terminal, and the ground jumper to the top terminal. Give 12 volts to the ICV either by pushing the button on a Power Probe, or whatever archaic method you wish to use.

 

This should close the ICV. The action should be very quick and snappy.

Swap the ground jumper to the bottom terminal. Once again, give the ICV 12 volts.

 

This should open the ICV. The action should be very quick and snappy.