3.2 Can't Hold idle sounds like a cylinder missing | Page 4 | FerrariChat

3.2 Can't Hold idle sounds like a cylinder missing

Discussion in 'Mondial' started by moysiuan, Apr 12, 2020.

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  1. spicedriver

    spicedriver F1 Rookie

    Feb 1, 2011
    3,859
    Then you put it back together and it's leaking fuel all over the place.
     
  2. mike32

    mike32 F1 Veteran

    May 13, 2016
    5,828
    Isle of man- uk
    depends on your fitting ability.
     
  3. sidtx

    sidtx F1 Rookie
    Owner

    Feb 9, 2014
    4,454
    Frisco, Tx
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    Sid
    We (my adult son and I) rebuilt the fuel distributor in my 85 QV -- this was after we lost the front bank completely.

    We ruled out the ECUs (switched cables). Installed new coils, distributors, rotors, caps, plug wires, plugs -- and none of it helped.

    Fuel pressure was good into the distributor -- however, pressure out to the cylinders was all over the place -- especially to the front bank of cylinders.

    We rebuilt the distributor using a kit we bought. Apparently we didn't do it right, as the problem got worse.

    So, I took a chance and ordered a "rebuilt" distributor off ebay:

    https://www.ebay.com/itm/100-Back-NEW-DIAPHRAGM-1YR-Warranty-FERRARI-FUEL-DISTRIBUTOR-328-MONDIAL-3-2QV/202657250402?hash=item2f2f503c62:g:6WEAAOSw1RVaiqFi

    After some tuning with the air/fuel setting (on top of the distributor, hiding under the little cap), the engine started and runs great.

    I still have my old fuel distributor, and my try to rebuild it again.

    Sid
     
  4. moysiuan

    moysiuan F1 Rookie
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    Nov 1, 2005
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    Canada
    Great link, thank you.
     
  5. moysiuan

    moysiuan F1 Rookie
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    Nov 1, 2005
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    I the Ferrari Bosch manual, there are various ECU tests on page 69, the specs refer to "Full scale deflection" and "Values". What does this mean? For example, the spec for the resistance of the elecgromagnetic pressure adjuster is Full scale deflection 200 ohm, Values 19÷20 ohm. Can someone explain how to interptret this correctly?
     
  6. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
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    Jan 11, 2001
    25,039
    30°30'40" N 97°35'41" W (Texas)
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    Steve Magnusson
    It means "Set your multimeter to the 200 Ohms scale, then when you make this measurement, the value measured should be between 19 and 20 Ohms".

    ("deflection" is a term used back in the days of ancient history when multimeters had a moving needle ;))
     
  7. moysiuan

    moysiuan F1 Rookie
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    Ah, makes sense. I still have an old needle meter, maybe I should use that one for the full in period experience.:)
     
  8. spicedriver

    spicedriver F1 Rookie

    Feb 1, 2011
    3,859
    I believe you are measuring a coil there. It could be open, or shorted, or at the correct value.
     
  9. moysiuan

    moysiuan F1 Rookie
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    #84 moysiuan, Apr 24, 2020
    Last edited: Apr 24, 2020
    OK, perhaps making progress. Failed fuel ECU???

    I have been doing the various voltage tests on the fuel ecu connector. Under test 17 on page 70 of the Bosch KE3 manual, the test calls for 5 volts between pins 35 and 9 (and pin 35 and others but my others are blank, so only the 35/9 pins can be checked).

    Being careful to make sure I am following the procedures, ie. the ecu connector on the ecu, and the ignition in drive (being the second "on" position, just before starting the car) position, I am getting a 0.001 volt reading. Did this few times to make sure I am not getting a poor connection to the volt meter, and used a second voltmeter just in case. The manual notes that if outside the 5 volts, there is a fault in the ecu itself.

    For greater certainty, before I try to find a new ecu (anyone have one these on hand?), test 13 calls for "Bypass in interrupted mode with external cable bewteen 18 abnd 15 and check corresponding ticking of the solenoid operated injector. Turn ignition key to neutral position. Connect ecu to the connector. Turn ignition key to drive position."

    When I did my test number 17, I presume the way the manual is written, on completing the bypass for test 13, one removes the bypass, then turns the ignition to neutral, connects the ecu and then turn the key to drive and then proceed to tests 14 through 18. This is what I did, with the test 17 anomoly noted.

    Have I interpreted this all correctly? I want to be absolutely certain I am measuring correctly before presuming the ecu failure.

    I also got some slightly odd readings on test 16: the pot on the mixture control unit, was getting .o3 volts at rest (should be zero) and 4.58 volts at full open of the air flow sensor, should be 4.8 to 5.2 volts, so was a tad low. Not sure if this is significant. On the throttle valve microswitch, on test 6: I was getting 1.3 ohms at idle (spec is 0.2 ohms) and 843 ohms at full throttle (spec is >1,ooo ohms); and test 7, was getting 0 ohms at idle, and .6 ohms when throttle was opened. I also got a slightly higher ohms for the grounding tests 1,2 3 and 3 , getting about .5 ohms rather than the spec .2 to .3 ohms. All other ohm and volt tests with the car in neutral or drive key position are in spec. I was unable to do the various other tests that call for the car to be started.

    Any advice for greater certainty on doing these tests? Does the ECU unit itself need to be grounded for the tests, I had to remove the unit from its bolt on mounting to be able to get at the pins for checking, I did remount for the key test 17 and got the same close to no voltage. Does neutral key position mean the first click to "on" but before the second click "drive" position? Just want to make sure I am not losing anything in translation of the manual procedures.

    The good news is I may have an identifiable unit failure. But I do want to be really sure of this!
     
  10. mike32

    mike32 F1 Veteran

    May 13, 2016
    5,828
    Isle of man- uk
    Mine still does have a moving needle, has technology moved on and i have missed it ? These big old black AVOs last for ever.
     
  11. mike32

    mike32 F1 Veteran

    May 13, 2016
    5,828
    Isle of man- uk
    That is a good price for a rebuilt one, last time i looked in uk they wanted £1800 for a new one.
     
  12. Subito Grigio

    Subito Grigio Formula Junior

    Jun 2, 2009
    327
    The travel time between Toronto and RPM in Vermont is about seven hours..... unless the border is closed....


    Sent from my iPhone using FerrariChat
     
  13. spicedriver

    spicedriver F1 Rookie

    Feb 1, 2011
    3,859
    I would guess that by just unplugging the electrical connector to the Magnetic Actuator, that would produce the same symptoms as a faulty Injection ECU. You can try that as another test.
     
  14. MvT

    MvT F1 Rookie

    May 25, 2013
    4,248
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    Tijn
    There are some guys in the US that can fix broken ECU units (need to look it up) I also know someone in NL as a last resort. he does this already for more then 25 years.
     
  15. MvT

    MvT F1 Rookie

    May 25, 2013
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  16. jkstevens2

    jkstevens2 Formula Junior

    Aug 25, 2015
    278
    Winter Park, FL
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    JK Stevens
    I am anxious the read the next chapter of this Ferrari diagnostic saga. Any new updates?
     
  17. moysiuan

    moysiuan F1 Rookie
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    Ineed JK, I am also anxious as to how all this turns out!

    New ECU on special order via Eurospares. Will take about three weeks to get it, so my story will drag on a while. I am crossing my fingers that my diagnosis of an electrical fault in the ECU was done correctly (as described in my previous post), and that the fuel ECU is indeed the problem.

    I am concerned that maybe some other system component failed and caused the ECU failure? But that is what the protection relay is supposed to prevent, so hopefully I am dealing with a cause and not a symptom.

    I also purchased as a spare a used ignition ECU for my inventory via Redbay, which will also allow me to definitively rule out the ignition ECU as a problem, although I have moved beyond spark and solely focussed on fuel issues for now. Other fuel injection related spare parts are also on the way. Also, with regards to the KE3 magnetic actuator noted by Spicedriver, where would one get this part from if it was needed?
     
  18. jkstevens2

    jkstevens2 Formula Junior

    Aug 25, 2015
    278
    Winter Park, FL
    Full Name:
    JK Stevens
    What is a "ignition ecu"

    What is a KE3 magnetic actuator?
     
  19. moysiuan

    moysiuan F1 Rookie
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    The ignition ecu is the Bosch Microplex unit, there is a separate one for spark, another for fuel injection which is the one that has apparently failed on my car (and another for the ABS brakes), so three computers in total on my 1988 Mondial 3.2. The magnetic actuator is the electrically connected device on the fuel distributor, unique to the KE3 fuel injection, and performs the same task as the frequency valve on the earlier Bosch KE fuel injection systems, which is what most Mondial and 308/328 owners have. My Swiss market Mondial is among the minority of the the Mondial series that has the later KE3 fuel injection. The KE3 operates at higher pressures, has different higher pressure fuel injectors and some unique fuel injection controls and actuators.
     
  20. jkstevens2

    jkstevens2 Formula Junior

    Aug 25, 2015
    278
    Winter Park, FL
    Full Name:
    JK Stevens
    I apologize, I am more familiar with my 86 Mondial 3.2 which has the one ecu in the trunk area?? I did not realize that the modial went to multiple ecu's prior to the Mondial T.

    As for the magnetic actuator, can you look on ebay for older model mercedes sl models. I know they used the same bosch fuel injection systems. I found an un-used frequency valve on ebay for $275ish using that search criteria and the actual bosch number on the top plastic ring of the freq. valve.
     
  21. spicedriver

    spicedriver F1 Rookie

    Feb 1, 2011
    3,859
    No, you've got the microplex as well. Access through the left rear wheel well. 2 ECUs

    +1 for getting the numbers off the magnetic actuator. It looks as though Ferrari sells this along with the mixture control unit (fuel distributor). You might have to buy a used mixture control unit, and take the magnetic actuator from there.

    https://www.allferrariparts.com/tbl14163.html
     
  22. jkstevens2

    jkstevens2 Formula Junior

    Aug 25, 2015
    278
    Winter Park, FL
    Full Name:
    JK Stevens
    Spicedriver......what is the 2nd ecu for?
     
  23. jkstevens2

    jkstevens2 Formula Junior

    Aug 25, 2015
    278
    Winter Park, FL
    Full Name:
    JK Stevens
    Spicedriver......the 2nd ecu you are referring is the microplex ignition control unit, got it
     
  24. Jeka

    Jeka Formula 3
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    Nov 20, 2010
    1,176
    Rotterdam
    Full Name:
    Johan
    I found the KE3 schematics and was puzzled by the missing 5 Volt in step 17 of the tests. There should be 5 Volt on pin 9 of the diagnosis tab. In the schematics this pin goes to the transistorized relay for the electrovalve which is actuated by pin 10. There is no test for this relays and valve in the manual. If that relay or transistor is defective there could be a low resistance to earth. If you want to be sure you can disconnect 203 which is the "interrupt for the lambda sensor" and do the step 17 measurements again. There might be a chance the 5 Volt will be available (if the relay is broken).

    Another test is to disconnect the connector of the injection control unit and measure the resistance (full scale deflection 100 ohm or 1 kohm) between pin 9 and 35 (internal earth) on the control unit. The measured resistance should be higher than zero to be sure there is no internal short circuit. The same for pin 2, 20 and 22 between pin 35.
     

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