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  1. F1ScuderiaTifosi

    Mar 16, 2015
    120
    Hill Country TEXAS
    Full Name:
    JB
    #1 F1ScuderiaTifosi, Nov 16, 2019
    Last edited: Nov 16, 2019
    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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  3. F1ScuderiaTifosi

    Mar 16, 2015
    120
    Hill Country TEXAS
    Full Name:
    JB
    #2 F1ScuderiaTifosi, Nov 16, 2019
    Last edited: Nov 16, 2019
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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!
     
    ernie, 308 GTB, GSF355 and 2 others like this.
  4. MAD828

    MAD828 Formula 3
    Silver Subscribed

    Oct 8, 2011
    1,851
    Sydney
    Full Name:
    Elliott Caras
    Nice work. Did this have any benefit to your idle issue? Edited as I just saw your updated post.
     
  5. F1ScuderiaTifosi

    Mar 16, 2015
    120
    Hill Country TEXAS
    Full Name:
    JB
    #4 F1ScuderiaTifosi, Nov 16, 2019
    Last edited: Nov 16, 2019
    Thanks, MAD828!
    Sure did! Thankfully!
     
  6. Ferrarium

    Ferrarium F1 Rookie
    Rossa Subscribed

    Jul 28, 2018
    2,919
    Central NJ
    Full Name:
    Eric
    #5 Ferrarium, Nov 16, 2019
    Last edited: Nov 16, 2019
    Tons of videos on this as well. I use a non chlorinated cleaner. Some videos out there on how to test them electrically as well.
     
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  8. F1ScuderiaTifosi

    Mar 16, 2015
    120
    Hill Country TEXAS
    Full Name:
    JB
    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?
     
  9. Qavion

    Qavion F1 Rookie
    Silver Subscribed

    Feb 20, 2015
    4,874
    Sydney
    Full Name:
    Ian Riddell
    Does the idle control valve default to fully open with no power? The idle seemed high with the plug removed. Low with it powered (but not lubricated). Medium with it powered and lubricated.

    I previously assumed the engine would stall with no power to the valve. Perhaps fully open is a failsafe.
     
  10. ernie

    ernie Two Time F1 World Champ
    Lifetime Rossa Owner

    Nov 19, 2001
    22,062
    The Brickyard
    Full Name:
    The Bad Guy
    Love it!
     
  11. F1ScuderiaTifosi

    Mar 16, 2015
    120
    Hill Country TEXAS
    Full Name:
    JB
    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.
     
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  13. F1ScuderiaTifosi

    Mar 16, 2015
    120
    Hill Country TEXAS
    Full Name:
    JB
    Thanks, ernie!
    Much appreciated.
     
  14. Ferrarium

    Ferrarium F1 Rookie
    Rossa Subscribed

    Jul 28, 2018
    2,919
    Central NJ
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    Eric
    The engine won't stall but it will run rough. I think the IAC motor is constantly opening and closing on a sliding scale to keep idle consistent, it's neither open or closed but in between.

    There was a real nice video on a test bench for IAC testing, I cant find it but I found this one.
     
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  15. F1ScuderiaTifosi

    Mar 16, 2015
    120
    Hill Country TEXAS
    Full Name:
    JB
    Interesting, I didn't know that. Thanks for the video, Ferrarium. Thankfully it's not a silent film, LOL!
     

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