308QV Fast Idle System Problems - HELP | FerrariChat
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308QV Fast Idle System Problems - HELP

Discussion in 'Technical Q&A' started by kdross, Mar 7, 2004.

  1. kdross

    kdross Formula Junior
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    #1 kdross, Mar 7, 2004
    When I start my car (1985 308QV USA version) the idle is suppose to be about 2,500 rpm until the engine is warm. However, when I start my car cold the idle is at 1,000 rpm's for about 30-60 seconds. After that time the idle goes down to 500 rpm's for about 10 minutes. After 10 minutes when the car is warm, the idle returns to 1,000 rpm.

    During the past two weeks I though my Aux Air Valve was bad. I tested the AAV and it checked out OK. Today while in the shop, we noticed that the cold start air valve that is connected inline with the AAV is missing on my car. It appears that someone removed the cold start air valve and bypassed the high idle system. This appears to be the reason why my cold idle RPM is so low.

    Does anyone know where this part is suppose to be located in the engine compartment and where the electrical connection is? I show my car at FCA events and I need to keep everything 100% stock. If anyone can take detailed pictures of a USA 308QV engine, I would be very interested in looking at the pictures. I would like to see exactly how this part is piped in and where it is located. I also need to know where the electrical source is for the cold start air valve. Please feel free to email them to me at kdross@msn.com Also, I do not have a cat on my car (it was hollowed out by the previous owner).
     

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  2. cinquevalvole

    cinquevalvole Formula 3

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    #2 cinquevalvole, Mar 7, 2004
  3. kdross

    kdross Formula Junior
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    #3 kdross, Mar 7, 2004
    cinquevalvole

    Thanks, but that is not my problem. I am the one that started the thread, but the AAV is not my problem. There is another part, the cold start air valve, that appears to be the problem.

    Ken
     
  4. carlrose

    carlrose Formula Junior

    Nov 25, 2003
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    #4 carlrose, Mar 7, 2004
    Hi Ken,

    Just for clarification: KE-Jetronic warm-up components:

    AAV
    Thermo-time switch
    CS injector
    Coolant temp sensor

    There's also the air injection system for filtered air input into the exhaut manifolds during warmup.

    Are you thinking the CS injector as cold start valve?

    :) Carl
     
  5. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
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    #5 Steve Magnusson, Mar 7, 2004
    Ken -- Are you sure yours is "missing". I'm having a flashback that the '83 US has the cold start air valve, but the '84-'85 US do not.
     

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  6. kdross

    kdross Formula Junior
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    #6 kdross, Mar 7, 2004
    Steve:

    That is a good question, and that is why I am trying to hear from other 1984-85 owners. The factory workshop manual I have for my QV is for the QV series, but it relates to the 1983 models because it mentions the air pump (which only the 83 cars have). Until I can see another 84-85 car, I will not know for certain whether or not my car is missing the cold start air valve. My owners manual just states that the high idle system is "automatic" and does not require any adjustment.

    Ken
     
  7. 308GTS

    308GTS Formula 3

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    #7 308GTS, Mar 7, 2004
    84-85 did not have this device. 83 however does. You have an AAV no vacuum limiting device.
     
  8. enjoythemusic

    enjoythemusic F1 World Champ

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    #8 enjoythemusic, Mar 7, 2004
    Ken,

    If no one chimes in by tomorrow, i can take high-rez pics of seaction(s) of my engine and post them here for you. Simple let me know specifically WHERE to photograph.

    Enjoy the Drive,

    Steven R. Rochlin
     
  9. 308GTS

    308GTS Formula 3

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    #9 308GTS, Mar 7, 2004
    Cold Start Injector is not the same thing. CSI sprays extra atomized fuel during cold cranking an stays on for a few seconds then stops spraying.
     

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  10. kdross

    kdross Formula Junior
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    #10 kdross, Mar 7, 2004
    Steve:

    Thanks a million for your offer to post pictures. I will take pictures of my car tomorrow and illustrate what I need to compare with my engine compartment.

    Ken
     
  11. enjoythemusic

    enjoythemusic F1 World Champ

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    #11 enjoythemusic, Mar 8, 2004
    Ken,

    Cool post away and i can offer HIGH rez via e-mail (PM me your e-mail addy) and i'll post the low res pics here. ALWAYS glad to help.

    Enjoy the Drive,

    Steven R. Rochlin
     
  12. carlrose

    carlrose Formula Junior

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    #12 carlrose, Mar 8, 2004
    Ken - had a thought last night - have you checked your fuel pressure when cold? Cold control pressure at WUR should be lower (about 20psi) providing less "counterpressure" on piston in fuel distributor when cold (more fuel delivery for given RPM) than when hot (about 51psi). This could potentially account for lower RPM with properly-functioning AAV.

    :) Carl
     
  13. gyrokeith

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    #13 gyrokeith, Mar 10, 2004
    My 85 308qv is also performing the same warmup scenario.

    800 miles ago when I purchased it the warmup was normal..2500 decreasing to about 950 when warm. Now she starts out at a balky 1000 rpm and drops before stabilizing at 1000. I'll be unpacking it soon and am very interested in what you find.

    I didn't see an AAV on my car anywhere... don't think there is any there.. my car is bone stock the best that I can tell... well... I did put a K&N on it..
     
  14. gyrokeith

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    #14 gyrokeith, Mar 10, 2004
    I meant it doesn't have a cold start air valve...

    Silly me...
     
  15. f355spider

    f355spider F1 World Champ
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    #15 f355spider, Mar 10, 2004
    You can test the AAV by pinching the hose to it under cold idle (right after starting) and see if has any impact on the idle speed. If not, likely it is stuck closed. You can remove it (under the coolant tank), and try cleaning and lubing it. Otherwise replace it. As others said, the WUR could be at fault too, and only pressure testing will say for sure.
     

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