Poor idle | FerrariChat

Poor idle

Discussion in 'Mondial' started by decardona, Jun 13, 2017.

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  1. decardona

    decardona Formula 3

    Apr 23, 2005
    1,019
    PA
    Full Name:
    Dennis Cardona
    I'm having a consistent problem. When I start up my car is fine. Idles well and consistent. Upon driving and getting to temperature the idle gets very low when coming to a stop. 500 or less. It feels as if it wants to stall. I throttle tap and it comes back, but if happens almost every time I come to a stop. The car is a 3.2. Any ideas? Thanks.
     
  2. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    25,040
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    #2 Steve Magnusson, Jun 13, 2017
    Last edited: Jun 13, 2017
    Is this:

    A. A problem that appeared suddenly - i.e., everything was working fine for a while, and then this symptom started, or

    B. It's always been this way since the last time someone messed with all the adjustments?

    Edit: Bigger question - just noticed that you have an SA version, which (from the SPC) is no cat, no Lambda (no O2 sensor, no frequency valve, no K-Jet Lambda ECU), no air injection, but with vacuum limiting valve (so essentially a K-Jet without Lambda set-up). Is your SA version: 1) completely unmodified, 2) modified to be US legal, or 3) was modified to be US legal at one time, but has since been further molested in some unknown way ;)?
     
  3. Wade

    Wade Three Time F1 World Champ
    Owner

    Mar 31, 2006
    32,793
    East Central, FL
    Full Name:
    Wade O.
    #3 Wade, Jun 13, 2017
    Last edited by a moderator: Sep 7, 2017
    Steve, as a refresher, here's the baseline from Jan 2015:

    http://www.ferrarichat.com/forum/technical-q/475731-mondial-3-2-k-jet-o2-sensor-control-system.html

    The "project" pretty much ended there when I discovered the root of the [vacuum] problem, a rusted vacuum reservoir.
    .
    Image Unavailable, Please Login
     
  4. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    25,040
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    So does that mean you never got the frequency valve to work?

    Did you ever confirm/deny if the injection ECU was receiving +12V power from somewhere?

    The single green wire sure does look like it should go to the single signal wire of the O2 sensor -- does it?

    Are you saying you never had the symptom decardona is reporting (after fixing the vacuum leak)?
     
  5. Wade

    Wade Three Time F1 World Champ
    Owner

    Mar 31, 2006
    32,793
    East Central, FL
    Full Name:
    Wade O.
    Correct on all i.e. never got a chance to pursue any further other than some research. So, sorry that I can't help beyond that. The car was back to it's normal, excellent running self after I replaced the canister.

    http://www.ferrarichat.com/forum/mondial/476277-hvac-doors-flapping-about.html

    While I was tempted to restore the car back to OE (as it left the Factory and undoing the import conversion), I didn't have the time to do so. And then I bought a 348, and no longer needed a 2+2 Ferrari.
     
  6. spicedriver

    spicedriver F1 Rookie

    Feb 1, 2011
    3,859
    Sounds like the linkage is getting hung up. Get the low idle symptom to show up, then pop the hood, and see where the throttle plate is exactly. Is it all the way closed ? Then do the throttle tap and recheck the throttle plate position again. I'll bet the tap causes the throttle plate to rest in a different position.
     
  7. decardona

    decardona Formula 3

    Apr 23, 2005
    1,019
    PA
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    Dennis Cardona
    Steve, the problem just popped up in the last couple of months. Prior to that it was smooth all the time. Wade made me aware of the things he did/changed on the car and I checked those items and they seem to be fine. The throttle plate position is something I will look at next. Hopefully it's something that's not going to be too problematic to fix.
     
  8. spirot

    spirot F1 World Champ

    Dec 12, 2005
    14,501
    Atlanta
    Full Name:
    Tom Spiro
    if this is just sudden, it sound more like an air leak in one of the vacuum hoses. Aux air valve, or something along those lines. also check the Frequency relay & fuse on the control panel - not sure where this is located in the Mondial, but in the 308's its under carpet on the passengers side of the trunk area. But my bet is going to be an air leak. next would be electrical. then mechanical... doubt its the throttle housing as if it were stuck open you would have a higher idle... if it was not returning or returning too closed you would have stalling.
     
  9. mike32

    mike32 F1 Veteran

    May 13, 2016
    5,829
    Isle of man- uk
    First off checkt the throttle cable to the engine bay, you will see a spring loaded quadrant on top of the engine. These have a habit of getting a bit stuck, give it a shot of wd 40 and check it moves easy.
    Other thing is to put some injector cleaner in the fuel tank- if no change then try some of the other items previously mentioned. It might be just something simple
     
  10. decardona

    decardona Formula 3

    Apr 23, 2005
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    Dennis Cardona
    Thanks for all the input. Will be working on it this weekend. Will let you know what it turns out to be. Thanks again.
     
  11. ronfrohock

    ronfrohock F1 Rookie
    Owner Rossa Subscribed

    Aug 16, 2004
    3,919
    MA
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    Ron Frohock
    Whenever I see Steve chime in, I pay attention. He has proven to be very knowledgeable and very generous with his time in the past. I can tell you that he has helped me more than a few times with odd problems that I have faced.
    I'll be following this closely.
     
  12. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    25,040
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    That's very kind of you to say Ron -- and this one won't be easy because it's been seriously modified (and that may not have been done correctly) and who knows what else now ;)

    IMO, the OP is going to have to decide whether to leave it operating as a K-Jet without Lambda (and it surprises me that was ever working OKish in that manner if it didn't have a VLV and had a K-Jet with Lambda WUR installed), or try to get working as a K-Jet with quasi-Lambda as it was once modified to be.

    OP:

    1. Can you post a (some) more complete picture(s) of the engine? (Wade's picture only showed the fuel distributor area -- would be interested to see if a VLV and/or a throttle microswitch is present or not.)

    2. Can you post the 10-digit Bosch PN shown on your WUR?

    3. If you do have a throttle microswitch present, try unplugging when you are at 1000 RPM warm idle (if it's working, I think something should happen ;)).
     
  13. Wade

    Wade Three Time F1 World Champ
    Owner

    Mar 31, 2006
    32,793
    East Central, FL
    Full Name:
    Wade O.
    #13 Wade, Jun 14, 2017
    Last edited by a moderator: Sep 7, 2017
  14. decardona

    decardona Formula 3

    Apr 23, 2005
    1,019
    PA
    Full Name:
    Dennis Cardona
    Steve, thanks for all the ideas. But, I tried some of the simpler ideas and the combination seemed to solve the issue. I put some fuel injection cleaner in and ran the car for a bit after. Then the next day I sprayed the throttle linkage with some carb cleaner and after being on the road for about 20 minutes, the problem was no longer there. Smooth idle, warm or cold, and upon coming out of gear when stopping. If it reoccurs, obviously, I need to get into the more technical things you suggested. I appreciate you taking the time to offer up suggestions. You were a help several times when I needed answers on my 308 and now on the Mondial. You are a great asset to those of us who try to DIY.

    Wade, thanks for your input on where the car stood under your stewardship. Although I have all the records, I don't remember all that was done off the top of my head, as you do. You stepping in with info right away is appreciated. Thanks again.
     
  15. Wade

    Wade Three Time F1 World Champ
    Owner

    Mar 31, 2006
    32,793
    East Central, FL
    Full Name:
    Wade O.
    The traditional "Italian Tuneup", in regards to your car, means shifting at redline. :)
     

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