How to clean ICV without removing it in 924s?

[mungodrums]

Hello,

I have a 1988 924s. I want to clean the ICV without removing. How can I do this? Please let me know what I need to use, carb cleaner, etc. Also, what needs to be unplugged, etc. Any pictures or video regarding how to do this? Little bit of idle issues. Generally idles a little fast at about 1100 rpm. Ger.

[wwdwgs]

Hi. In order to get to ICV you must remove air box, J-boot, intake manifold and other minor associated parts. Also, you may (or may not) need new intake manif. gaskets and rubber studs (bonded rubber mounting), that attach ICV bracket to engine (or whatever). There are some rubber hoses - some maybe brittle already... Generally, you'll find alot of interesting stuff under intake manifold.
When I was young and beautiful, I worked in that area, but didn't inspect, no serviced ICV. I may need to do that, as my idle is also high (just a tad less than 1000 prm) and adjusting idle screw is all the way down (almost).

Somewhere on this forum, someone cleaned ICV (on 911) and it didn't make any difference in idle speed.

[walfreyydo]

I dont think you can clean it without removing. But once removed, carb cleaner or brake cleaner is the ticket (spray some in and let it soak a bit, spray more until it comes out the other end clean). Use a 12V source to actuate it and make sure its moving quickly and freely.

[OK-944]

If after cleaning your ICV is still sluggish/unresponsive...you can bend the little metal tabs at the top and pull it apart - and in doing so just might find that the three brushes might need to be bent inward slightly in order to make fresh contact with the rotor, which itself can become somewhat "gouged out" over time.

If you do take your ICV apart...just make sure to re-install its O-ring - as this is necessary to preserve the vacuum needed to make this work!

[mungodrums]

I was hoping I could clean ICV without actually removing it. I have read of various individual's who supposedly cleaned ICV with carb cleaner by disconnecting one end of hose spraying it in, have it sit over night and start up next day. Just no pictures showing how its done. Any ideas? How about some system cleaner that cleans everything and also the ICV? Ger.

[walfreyydo]

Originally Posted by mungodrums

I was hoping I could clean ICV without actually removing it. I have read of various individual's who supposedly cleaned ICV with carb cleaner by disconnecting one end of hose spraying it in, have it sit over night and start up next day. Just no pictures showing how its done. Any ideas? How about some system cleaner that cleans everything and also the ICV? Ger.

Where does all the gunk go then? Right into your intake and combustion chamber.

[OK-944]

A fairly common symptom of an ICV going bad is an idle which "hunts," or cycles up and down an rpm range with no pedal pressure...typically after the engine has warmed up a bit.

Question: do you know when the air intake assembly was last removed? If not, have you at least carefully checked the condition of the two rubber hoses (particularly the short, S-shaped hose), located under the intake, which are connected to the ICV? I ask because its fairly common for those hoses to become cracked with age and remain that way as they go unnoticed under the intake.

While carefully inspecting those hoses is obviously easier with the intake assembly removed...you can do a decent job of this while the assembly is in place, with a strong light and inspection mirror...as you deflect the hoses around with a non-invasive probe (like the eraser end of a pencil) to see if any cracks open up.

[Monkey Wrench]

If you compare that part to the volvo 240 or 740 I think it's the same part. . I think Volvo used a couple of slightly different ones, you cna look it up and see if it physically resembles yours. If so it just may provide some alternate parts sources.

It has a 12 V connector.. what Ive done in the past is just clean it out with some sea foam.
and yes those hoses that handle crankcase fumes and are 25 years old will be most likely turned to garbage and may have holes etc. I dont remember ever connecting power but I assume it's just a valve that opens and closes so you could check it's function.

if the intake manifold has to come off , Id say , so be it ,, and you might want to clean the throttle body, check hoses etc in the area..

I think if you dump a bunch of cleaners down there it will end up in the oilpan but may also cause worse hose rot.. If you can get to the hose connectors you could try connecting a rad hose temporarily maybe?

by the time you mess around you can likely just remove the manifold and check and clean it out of the car. I have seen volvos of similar age where hoses were completely torn open and turned to goo and it was hard to see without removal.

here's a short video of it being done on a Volvo
https://www.youtube.com/watch?v=s-yGNPf_uus&ab_channel=LongbowMedia

heres one being removed from an S2
https://www.youtube.com/watch?v=yHAajWoRV6E&ab_channel=JohnCooper

in this one a guy connects power while it's out of the car and you can see how it works better..

https://www.youtube.com/watch?v=30Ctw8BoNog&ab_channel=aDIYCarGuy

I think I figured it was a solenoid, maybe it is a motor. it seems to be powered in either direction. , it doesn't seem hard to see if it's stuck or not functioning, if it's out of the car.

in this video he shows an early 944 one which has only two wires and that one looks different from a volvo..

https://www.youtube.com/watch?v=lO-roJQNz0o&ab_channel=MichaelODonnell


so to sum up , some seem to have 3 wires, others have 2 wires so if you remove the plug you should be able ot tell which you have. it might be a motor or a solenoid. the Video of the s2 shows it being removed removed without removal of the manifold.

you may or may not find the part is shared with the Volvo 240 or 740, It's a bosche part. You might compare part numbers etc..

there might be an engine temp sensor involved in its operation so maybe that can be tested too. It seems ot be adjusting the air fuel mixture so it works a bit like a choke allowing a richer mix when cold.

I think air that can bypass the air mass meter or barn door is going to make the car run leaner so it might be closed when the engine is cold and open to allow a "normal mix" when the engine is warmed up.

problems in this area could cause hard starting, it may be comparable to a choke getting stuck open in a carb engine and it firing but not starting so easily, leaks may mess with the air-fuel miixture.. maybe cause idling issues.. ?