355 2.7 Idle Control Valve Cleaning...

I thought I accidentally deleted these photos but I apparently saved them in an incorrect folder. There is probably a sticky about this but I didn't find it so I'm posting how I did the work.


SYMPTOM:

After warm ups, every once in a while, her idle would be a little rough. I suspected the culprits were dirty Idle Control Valves (2.7 Ferrari P/N: 147373 & Bosch P/N: 0 280 140 527) so I blocked off a couple of hours to tackle the job.

I first removed the 8 flathead screws (4 per airbox on a 2.7) securing the 2 upper airbox housings and unsecured the 4 (2 per airbox) latches joining the airboxes to the MAF sensor housings. I separated the upper airbox housings from the MAF sensor housings and set them aside. I was careful not to drop the airbox screws.

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Next I loosened the 2 hose clamps (6mm) securing the accordion style air hoses to the plenums. I did not loosen the hose clamps securing the air hoses to the MAF housings. After I separated them from the plenums I rested the assemblies on the area in front of the lower airbox housings being careful not to strain the wires for the MAF sensors as I did not disconnect the MAF connector.

*I removed the assemblies to give my hands a bit more room to access to the idle control valve connectors. I could have probably avoided the removal of these assemblies but I figured I'd inspect the air hoses for cracks since I was in there.

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I unplugged the idle control valve connectors and inspected the prongs for any corrosion.

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I removed the 10mm nuts and washers (1 nylon locking nut and 1 washer per bracket) securing the brackets to the bottom of the plenums. I was careful not to drop the nuts and washers.

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Next I loosened the 2 hose clamps (6mm) securing the (U-shaped) air hoses from the idle control valves to midway up the plenums. At this stage I did not yet loosen the clamps securing these hoses to the idle control valves.

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The idle control valves, along with the air hoses, were now loose enough for me to wiggle off of the plenum. Once I wiggled them off, I set the brackets, rubber bracket sheaths and rubber idle control valve sleeves aside. I also loosened the hose clamps securing the air hoses onto the idle control valves then wiggled the hoses off.

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Here are before & after photos of the internal mechanism in the idle control valve. Both the drivers and passengers side valves were similarly grimed up so I only photographed one of the valves. The 'after' photos are the results of the initial cleaning. I had to make a run to the store to purchase more carburetor cleaner to get them even cleaner. I got them gleaming but I didn't bother taking another set of pictures, sorry.

I cleaned the idle control valves by spraying the internals with the carburetor cleaner and using Q-tips to scrub. I was able to flush out and scrub off a lot of carbon buildup. The mechanism rotates in the housing. I manually rotated the mechanism with a screwdriver but was careful not to damage any of the surfaces.

*Whenever I sprayed the internals I made sure the input & output ends faced downwards to prevent any leakage into the other end of the idle control valve's housing because that end contains the electronics. I'm not sure if positioning them in that way matters during cleaning but it made sense to me.

BEFORE:


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AFTER:

 

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After I finished cleaning & drying both of the idle control valves I reversed the disassembly process to get everything back together. Done. Down a beer.

*I also dabbed each one of the idle control valve prongs with petroleum jelly to prevent any potential future corrosion.

Did the cleaning smoothen out the rough idle? Sure did!

 

Thanks, MAD828!
Sure did! Thankfully!

 

Yeah I saw that video. I stopped watching it because completely non-commentary videos bore the heck out of me.

Interesting. Are there advantages to using non-chlorinated cleaner over carburetor cleaner?

 

Was that question for me or Ferrarium because I don't know the answer to that. I don't unplug things that are supposed to be plugged in when the vehicle is running, LOL. But I would've assumed the same as you that the engine would stall.

 

Thanks, ernie!
Much appreciated.

 

Interesting, I didn't know that. Thanks for the video, Ferrarium. Thankfully it's not a silent film, LOL!