Cleaning The Iac Valve And A Basic Engine Cleanup

[The Don]

Here is a Top Gear like bombshell, if you are a member of Auto Lanka, buy Mitsubishi Lancer (CA-CS). Why, because there more support for those models in here than any other model of vehicle

[VVTi]

In a ideal world, one should not remove the ICV In the Subaru if it comes off and is not put in the exact same way, you are in for a world o f hurt. The boxer anyway has a slight uneven idle. This gets worse. The only cleaning it gets is via the TB, with a liberal spray of TB cleaner.

[The Don]

In a ideal world, one should not remove the ICV In the Subaru if it comes off and is not put in the exact same way, you are in for a world o f hurt. The boxer anyway has a slight uneven idle. This gets worse. The only cleaning it gets is via the TB, with a liberal spray of TB cleaner.

This is the issue VVTI, ICVs should not be cleaned with TB cleaner. Lots of mechanics do it, because its very good at melting away the carbon, but a lot of ICVs have also failed as a result. This could be a Mitsubishi problem, as certainly JD had no issue with his Mazda, but you need to exercise caution. I actually had a chat with JD after he posted this article originally, and pointed out the issues with the cold idle advance, and possible damage to the ICV from carb cleaner.

[Davy]

The chances of an ICV failing after using carb or throttle body cleaner on it depends on how it's cleaned also. If the TB cleaner is directly sprayed onto the ICV straight out of the pressurized can, chances are that the carbon that is already on the ICV could get pushed further into the actuator mechanism and even inside the bearing and the motor housing as well.

The UniMo contact of mine mentioned something similar to this even before he diagnosed the car. His words were that the carbon washed in by the TB cleaner probably caused the motor to get stuck. Thereby it would have overheated and caused one of the two coils to burn. I thought this was a logical explanation. I'm yet to get hold of a multimeter and check if the coils are intact. There are three tiny holes on the ICV to allow the motor to breathe and not overheat. This is probably where the TB cleaner leaked in.

Also, if you look closely at my dismantled ICV motor armature, the magnet is fully covered with a thick layer of carbon which probably was a result of TB cleaner pouring along the actuator and then into the mechanism.

So If you must clean the ICV, Use TB cleaner on a clean rag and wipe the ICV actuator with it carefully, making sure no TB cleaner gets anywhere close to the motor. Not sure if compressed air will help, but it should be better than spraying TB cleaner directly I guess.

[Rumesh88]

@Davy - I see this problem with stepper motors of this type (compared to the flap type in, for example,Toyotas) quite often in Mitsubishis and Pugs. Both the flap type and plunger type ICV uses a similar and well established technology, and I do not see how and why one can be more reliable than the other. But as I see it, the plunger type is more susceptible to effects of friction than its flap type counterpart, particularly on the lead screw of the motor. When a throttle body cleaner is used it can get leaked inside and wash off whatever lubrication that is there. So as you pointed out earlier whenever the throttle body is washed it is always better to take out the ICV to prevent solvents getting inside the mechanism. After all it may not be fair to attribute the failure to the type of the ICV. It could very well be due to the way it is cleaned. Do you agree with me?

Edit: Did not notice your above post before posting mine.

Edited April 11, 2014 by Rumesh88

[Davy]

@Davy - I see this problem with stepper motors of this type (compared to the flap type in, for example,Toyotas) quite often in Mitsubishis and Pugs. Both the flap type and plunger type ICV uses a similar and well established technology, and I do not see how and why one can be more reliable than the other. But as I see it, the plunger type is more susceptible to effects of friction than its flap type counterpart, particularly on the lead screw of the motor. When a throttle body cleaner is used it can get leaked inside and wash off whatever lubrication that is there. So as you pointed out earlier whenever the throttle body is washed it is always better to take out the ICV to prevent solvents getting inside the mechanism. After all it may not be fair to attribute the failure to the type of the ICV. It could very well be due to the way it is cleaned. Do you agree with me?

Edit: Did not notice your above post before posting mine.

Totally agreed! (as per my previous post). Looks like we've been thinking along the same lines at around the same time.