Testing IACV

[pletevl]

Hi all,

is there a way of testing the IAC valve used on the 4 cylindre K-series engines ?

I know there's 4 pins, inside there are 2 coils, 2 pins per coil.

putting 12 volts to these pins, should the inner part turn ? logic says yes, but I have a few here and none of them turn. Even one that I've taken appart.

So, does anyone know how to test it ? to see if the plunger moves up and down freely without sticking ?

Pete.

[SD1too]

Originally Posted by pletevl

I know there's 4 pins, inside there are 2 coils, 2 pins per coil.
putting 12 volts to these pins, should the inner part turn ?

Hello Pete,

What you have to do is to take a pair of pins connected to the same winding and apply +12v to one of them and earth to the other.

Alternatively, plug the stepper motor into the car's loom and switch the ignition on and off. Provided that the engine has been run previously, you should see the plunger move at one of those ignition key positions.

Because it's a stepper motor the plunger will move only through a short distance when you manually apply a voltage.

Simon

[Arctic]

Hi Pete.
Maybe have a read of this it may help

https://www.wikihow.com/Check-an-Idle-Air-Control-Valve

[pletevl]

Hi Simon,

What do you mean ? each time I apply 12v to one of the windings, the motor will not spin, only move a tiny amount ?

I have T4 and we have a TF that only ralely passes the idle test on T4

I have 3 IACV here, and none of them actually move when 12v are applied, I feel a little "thud" that the valve is getting power but the actual plunger does not move.

Pete.

[SD1too]

Originally Posted by pletevl

... each time I apply 12v to one of the windings, the motor will not spin, only move a tiny amount ?

Yes, that is what you should expect to happen. The device will never spin. It contains a stepper motor designed to move in short bursts. Each burst is triggered separately by the ECM by applying a voltage across each of the two windings in sequence in a positive or negative direction as required.
These rotary bursts are converted by a gearbox into longitudinal motion of the plunger and that is the only motion you will see.

Originally Posted by pletevl

I have T4 and we have a TF that only rarely passes the idle test on T4.

I'm not familiar with that test Pete. The IACV controls idle speed, nothing more. What exactly is the problem you're having?

Simon

[pletevl]

The problem with this TF is that when cold, it starts fine, then after about 30 seconds it starts to chug, engine revs start to drop, smells rich and stalls, can be difficult to restart, and then stalls again at a junction etc. Away from tickover it drives fine. Once up to temperature, it's fine.
T4 has a test where it will control the IACV once it's been set, the TF doesn't always pass this test.
I have changed everything I can think of, ECU coolant temp sensor, MAP sensor, oxygen sensor, plugs, leads, coils, there's no air leaks, ................................

[suzublu]

Ignition on, press accelerator pedal 5 times quickly, ignition off, then start the car

Sent from my SM-A145R using Tapatalk

[pletevl]

did this, T4 told me to do it :-)