Mondial 3.2 88 stall on cold start and run rich | FerrariChat

Mondial 3.2 88 stall on cold start and run rich

Discussion in 'Mondial' started by JspMondial, Jul 30, 2022.

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  1. JspMondial

    JspMondial Rookie

    Jul 17, 2022
    14
    Hello
    Just bought a Ferrari Mondial 3.2 1988 US version (4 weeks ago). Really happy and drove the car for 500 miles so far … I’m also new to the channel.

    The car always started , but since a week , I have an issue!
    2 seconds after cold start it stalls (goes from 1000rpm and slowly drop to 0). See the video below. I have to restart and then it’s ok (but the second restart is really long before it fires up).

    My observations so far :
    - car is smelly (too rich) when cold and even when warm
    - once the car is warm, it starts normal.

    I have read a lot on Ferrari Chat since my issue have other post that may be related. But not able to conclude so far. I’m not a mechanical technician, let’s say intermediate level , or beginner++ ;)

    I’m looking for a process to follow to troubleshoot the issue.

    Any help please ?

    Video of the cold start and stalls …
    https://share.icloud.com/photos/04fdZ_cJOuloc0hXByfBX7JKA


    Many thanks



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  2. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,785
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    #2 Steve Magnusson, Jul 30, 2022
    Last edited: Jul 30, 2022
    First, confirm/deny if the Frequency Valve is vibrating (by touching it) when the engine is cranking or running. If it isn't (because, for example, the Protection Relay isn't working) and someone tweaked it up warm with a dead Frequency Valve = warm running can be OKish, but cold running will be terrible:

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    Otherwise, you are left with the usual diagnostic steps for a K-Jet with Lambda system by checking the regulated fuel supply pressure, the WUR cold supply pressure, the WUR warm supply pressure, and then tweaking it up warm correctly.
     
  3. JspMondial

    JspMondial Rookie

    Jul 17, 2022
    14
    Thanks Steve for your help !

    Yes the Frequency valve is vibrating

    So done first K-jet test by disconnecting the CSI cold start injector and removing it from the socket and plugged my voltmeter in the connection.

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    START the engine from a cold start (you can see the video below)
    Temperature in Montreal is actually 25 Celsius

    It started normal :) yes ! Before this cold start issue, It started like that (maybe normal)

    So from my understanding it should not send voltage to activate the CSI because it is over 15 celcius

    My observations:
    . When I started , it gave 11 volt for 2 seconds to my voltmeter
    . The CSI (disconnected) never streamed fuel (which is normal since disconnected
    . The car started normal for the first time since a week !
    . less smelly … and getting better when warm , but still smell (let say 75% less)

    What should I do from here ?

    Video of my cold start without the CSI
    https://share.icloud.com/photos/0f7z82yeiTQlD9lvYrPEK-bxw




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  4. JspMondial

    JspMondial Rookie

    Jul 17, 2022
    14
    Forgot to say:
    My CSI is removed and the hole from where it fit is blocked with tape (to prevent an air leak)


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  5. theunissenguido

    theunissenguido F1 Rookie
    Owner Silver Subscribed

    Jan 21, 2004
    2,667
    Argent/Brasil
    Full Name:
    Guido
    I suspect a stuck plunjer inside the fuel distributor.
     
  6. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,785
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    #6 Steve Magnusson, Jul 30, 2022
    Last edited: Jul 30, 2022
    Can't agree with that. Service Bulletin 10-13 (which is Ferrari's description of how their implementation of Bosch K-Jet with Lambda works) indicates that the cold start injector will squirt during the initial starter motor cranking event until the engine (i.e., the Thermo-Time Switch) is at 45 deg C or above. This link will get you a copy of Service Bulletin 10-13:

    https://www.dropbox.com/s/hk5gupwre678a5q/Service Bulletin 10-13 Bosch K-Jet with Lambda.pdf?dl=0

    It would also probably help you to read Chapter D of the Mondial 8/QV WSM 281/83 covering Ferrari's K-Jet without Lambda as a prerequisite:

    https://www.dropbox.com/s/z99soo68ny9n2qa/Mondial8qv_workshop_281-83.pdf?dl=0
     
  7. JspMondial

    JspMondial Rookie

    Jul 17, 2022
    14
    Many thanks for the reference , I’m reading …

    Another question, since it is normal to send voltage to the cold start valve when my car temp is 25 celcius.
    Does 10.6 volts was ok ? Should it be 12.6 volts.

    I’m still trying to understand why it helped my cold start issue disconnecting the CSI. Maybe my CSI when activated, is not doing the right « spray shape »?




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  8. JspMondial

    JspMondial Rookie

    Jul 17, 2022
    14
    Thanks for your reply!

    Stuck plunger only in one chamber would cause my symptoms ? What would be the best to troubleshoot or to try to validate (or unstuck) the plunger ?



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  9. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,785
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    That's perfectly normal. When the starter motor is drawing 150A~200A from the battery, the battery voltage "droops" down due to the non-zero internal resistance of the battery itself. I'm guilty of this as anyone else, but we often say "+12V" when what we really mean is "whatever the proper battery voltage is for the conditions" which can vary from:

    During starter motor cranking = 9~10V is reasonable
    Just the battery by itself = 12~12.6V
    With the engine (and alternator) running = more like 13~14V

    I think you have a lot of clues that things are too rich, but there are many possible causes of excessive richness -- just tweaked-up too rich, a WUR that has bad behavior, an always stuck on CSI (although I think you indicated that was not the case and it did turn off electrically and wasn't leaking), etc.. Ensuring the airflow metering plate (and FD Plunger) move smoothly, easily, and repeatably (when there is no fuel pressure) as Guido suggested is certainly another easy basic thing to check. But if it seems OK, I think you're still left with making sure that the various fuel pressures are OK and in-spec before retweaking anything.
     
  10. JspMondial

    JspMondial Rookie

    Jul 17, 2022
    14
    Thanks again for your help.

    Will try that to verify if the airflow metering plate (D28) and FD plunger (D26) move smoothly and also verify my fuel pump electricity (will order a new fuel filter). Will do the CSI check procedure in the Manuel you referenced (D36) and come you back with result :)





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