California misfire at 4200 rpm on up | Page 2 | FerrariChat

California misfire at 4200 rpm on up

Discussion in 'Technical Q&A' started by PRO SYSTEMS, Apr 30, 2017.

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  1. Rifledriver

    Rifledriver Three Time F1 World Champ

    Apr 29, 2004
    33,736
    Austin TX
    Full Name:
    Brian Crall
    Cyl 2 is not on bank 2.

    An immobilizer performs none of those functions.
     
  2. james62

    james62 Rookie

    Sep 21, 2006
    5
    Ok. on bank 2

    Immobilizers will generally kill fuel or ign via the ecu generally through BCM.
    If its on the other bank sounds unrelated.

    Jim
     
  3. spicedriver

    spicedriver F1 Rookie

    Feb 1, 2011
    3,859
    That front mid-engine looks significantly harder.
     
  4. Andy 355

    Andy 355 Formula Junior

    Jun 2, 2013
    434
    Sydney
    Interested in how ignition misfires show a lean condition. This is not true. If you have a ignition misfire you have unburnt fuel in the exhaust. If you have a misfire and lean then its running out of fuel. I have seen this personally on Citroën/peugeot diag with faulty injectors.
     
  5. Andy 355

    Andy 355 Formula Junior

    Jun 2, 2013
    434
    Sydney
    Also be aware of the fact that once the ecu detects a misfire it most likely will turn off the injector. Late model benzes do that. That might be why your thinking its lean. Welcome to the new world of diagnostics. Back to basics. 1st up, smoke test the inlet manifold. Good luck too because that ain't easy either.
     
  6. Andy 355

    Andy 355 Formula Junior

    Jun 2, 2013
    434
    Sydney
    Egt will pinpoint the misfiring cylinders in any case. After a certain misfire count the ecu will shut down that cyls injector. Just so you are not pumping fuel into the exhaust system.
     
  7. PRO SYSTEMS

    PRO SYSTEMS Karting

    Mar 4, 2017
    54
    Miami, FL
    UPDATE: I replaced the #2 coil. NO effect.

    BUT found out that while the engine is still in closed loop (under 150 degrees on the temp gauge), it runs fine at wide open throttle all the way to redline.

    The warmer it gets, the problem returns gradually... with small misfires and then when fully warmed...hits right at 4200 rpm like clock work at anything over 1/2 throttle.

    Also, you can tell its not an injector thats being shut down as its an rpm limiting HARD misfire. Its aggressive. It sounds like a traction control system that uses a rev limiter to control
    excessive tire speed (I own a racing parts manufacturing company and I race cars that use these types of systems so thats the only way know to explain it) An injector shut down would simply be loss of power, unless I guess they slam the bank off and on. Its a hard misfire.
     
  8. INTMD8

    INTMD8 F1 Veteran
    Owner

    Jun 10, 2007
    6,488
    Lake Villa IL
    All of the above is incorrect.

    Yes if it misfires, it will show lean at WOT.

    Narrowband o2 at WOT will be 900+mv and spike lean every time there is a misfire.

    Graphing this is a good indicator of which bank is misfiring.

    Yes, there is unburned fuel but the o2 sensor is measuring oxygen and there is a hell of a lot more unburned oxygen than fuel when this occurs. Wot richer than stoich, still 12-1 or 11-1 air fuel ratio means 11 or 12 times more oxygen than fuel when not ignited, showing lean. The unburned fuel isn't even measured.





    One question I have is, it was said that fuel pressure is good. Are we talking the in tank pump supplying the high pressure mechanical pump or the high pressure side, rail pressure?

    If the high pressure side falls off with rpm injector pulsewidth increases to try and compensate for the pressure drop. If it drops too much you can end up eith EOI (end of injection) point overlapping spark ignition, resulting in a misfire.

    This would usually be accompanied by a fuel pump/pressure type code but I've seen cases where pressure drops enough for a higher rpm/wot misfire and no codes set.
     
  9. PRO SYSTEMS

    PRO SYSTEMS Karting

    Mar 4, 2017
    54
    Miami, FL
    Yes, thats correct, misfires will read lean when the ignition is cutoff.

    The fuel pressure at the rail is rock solid under a load. I had them go right to the rail and get data, so its not a fuel issue as delivered to the injector.

    I wonder if the system can actually sense a cylinder (or bank) being lean (as the system is aware of that bank being lean...but we don't know if its lean from the mixture OR lean from the ignition misfire).

    But if it can sense the bank being lean from too little fuel, is it setup so it will cut off the igntion in a random pattern (like a rev limiter cycles every other cylinder) in order to protect the engine from damage. Because thats what it feels and sounds like...a controlled and precise sounding and cycling rev limiter. It will still allow rpms to climb but its really trying to hold them down.
     
  10. INTMD8

    INTMD8 F1 Veteran
    Owner

    Jun 10, 2007
    6,488
    Lake Villa IL
    #35 INTMD8, May 7, 2017
    Last edited: May 7, 2017
    Does it have narrowband or wideband o2's? If it doesn't have wideband with closed loop fuel control at WOT it wouldn't be able to cut off ignition due to a lean condition as of course it wouldn't know.

    If the system would ever do that at all. Closed loop at WOT, first thing it would do is trim in as much fuel as possible. (if this system is capable of that)

    If it was the ecu limiting, you should be able to scan the source of torque managment/limiter.
     
  11. PRO SYSTEMS

    PRO SYSTEMS Karting

    Mar 4, 2017
    54
    Miami, FL
    It wide band. Very accurate wideband as well.

    Its definitely aware of torque It will display the torque values.

    The system is not performing a FUEL CUTOFF function.

    It has a P1572 code IDed as an Immobilizer Malfunction on Bank 2 (Invalid Signal)

    Greater than 4ms on Fuel injection when problem occurs.
     
  12. INTMD8

    INTMD8 F1 Veteran
    Owner

    Jun 10, 2007
    6,488
    Lake Villa IL
    I would start with eliminating the easiest and cheapest first. Change plugs and if no good see if it follows the coil.

    As mentioned, if it has closed loop fuel control at wot you would see positive fuel trims if it was trying to correct a lean condition
     
  13. PRO SYSTEMS

    PRO SYSTEMS Karting

    Mar 4, 2017
    54
    Miami, FL
    Interesting test I just performed that did not follow what it did yesterday. Yesterday when the engine was colder...it had no issues running right up to redline. So today I did very little warm up and took it out and it had that misfire starting at 3600 rpms. SO NOW we know its probably fuel delivery based.

    More than likely the dealer is correct, it is an injector spray issue and cleaning or replacing will fix it, I just wish they had more confidence when they were selling it to me. This is an engine out procedure to get to these injectors and if they are wrong... I am on the only one that loses.
     
  14. spicedriver

    spicedriver F1 Rookie

    Feb 1, 2011
    3,859
    I had a newer Chevy V8 that developed a misfire after warm-up. It turned out to be a sticking exhaust valve. An easy test for this is to hold an envelope close the the exhaust pipes. The exhaust should always push the envelope away. If it sucks the envelope back to the pipe, the valve is sticking open.
     
  15. Andy 355

    Andy 355 Formula Junior

    Jun 2, 2013
    434
    Sydney
    The engine is in open loop when cold.
     
  16. Andy 355

    Andy 355 Formula Junior

    Jun 2, 2013
    434
    Sydney
    Should the injector be injecting the correct quantity of fuel and the offending cylinder/cylinders drawing the correct amount of air than the "cylinder/cylinders" will be seeing the correct air/fuel ratio.

    Now, if you have an ignition misfire the wideband will be seeing an untrue lean mixture since the engine is essentially pumping air and unburnt fuel into the exhaust.

    Would you consider running on a dyno and measuring hydrocarbons as well first? This might help to isolate ignition misfire problems, before heading down the costly and time consuming injector path.
     
  17. PRO SYSTEMS

    PRO SYSTEMS Karting

    Mar 4, 2017
    54
    Miami, FL
    SO I ran the rpms up higher past 4200 to 6000 rpms. Now if it was a lean issue on my race cars (I do a lot of dyno testing etc...) from lack of fuel, the misfire should get progressively worse and many times turn into an intake manifold backfire as rpms increase... but instead, it stays exactly the same and is an amazingly consistent and controlled misfire or ignition interrupt.

    Question 1: Does the Ferrari engine management have the ability to interrupt ignition to protect the engine from damage in a lean situation OR is it a bad coil or ???

    It sounds the same out the exhaust no matter the rpm or throttle position. A steady rhythm. It just sounds so ignition based.

    Question 2: Cylinder # 2 (identified as a P0302 code), where is it located?

    Is it the passenger side front?
     
  18. INTMD8

    INTMD8 F1 Veteran
    Owner

    Jun 10, 2007
    6,488
    Lake Villa IL
    Now you got it :)
     
  19. PRO SYSTEMS

    PRO SYSTEMS Karting

    Mar 4, 2017
    54
    Miami, FL
    So it doesnt get lost in the shuffle, IF ANYONE KNOWS these answers it will really help get the situation pointed in the right direction.

    Question 1: Does the Ferrari engine management have the ability to interrupt ignition to protect the engine from damage in a lean situation.

    If not it could be a bad coil or ??? as it sounds the same out the exhaust no matter the rpm or throttle position. A steady rhythm. It just sounds so ignition based.

    Question 2: Cylinder # 2 (identified as a P0302 code), where is it located?

    Is it the passenger side front?
     
  20. GTHill

    GTHill F1 World Champ
    Lifetime Rossa Owner

    Jul 1, 2006
    14,053
    Double Wide
    Full Name:
    GT Hill
    How close are you to Texas?

    GT
     
  21. Fezza12cyl

    Fezza12cyl Rookie

    May 8, 2017
    1
    Hi there.

    Question one: Sorry I don't know how Ferrari has programmed the Ecu to respond to certain situations, however, you can use an oscilloscope to test the ignition outputs to prove if the signal is changing Above 4200rpm and 50% throttle.

    Question two: it may be possible to remove the wiring to the coil you suspect is number two, turn the ignition on and have a code for that cylinder being open circuit. Confirm that code identifies cyl number 2.

    I hope there is some help here.
     
  22. maxvonauto

    maxvonauto Karting
    Silver Subscribed

    May 23, 2015
    159
    Corona
    Full Name:
    Mark
    Any shop with a Ferrari diagnostic tool or good aftermarket software (like AutoEnginuity) should be able to find the problem if they know how to use them and properly interpret the results. Otherwise, you'll be just guessing.

    If the dealer says it's an engine out procedure check the factory manual (available online) to see if there's another procedure. Ive found many procedures in the 458 manual that most dealers conveniently don't even know exist!
     
  23. maxvonauto

    maxvonauto Karting
    Silver Subscribed

    May 23, 2015
    159
    Corona
    Full Name:
    Mark
    Note: the spark plugs on the 458 and California are special "ion sensing" plugs. They work in conjunction with the anti-detonation ECU to sense detonation and alter timing accordingly. I can't see how the system could pull enough timing to create such a hard misfire on one cylinder but possibly.
    That's why you need somone to data log all the pertinent parameters in real time during the miss fire to home in on the real issue.
     
  24. Motob

    Motob Formula 3
    Professional Ferrari Technician

    Nov 11, 2003
    2,238
    Frederick, Maryland
    Full Name:
    Brian Brown
    The California T and 458 have Eldor Ion ignition systems, which senses detonation through the spark plug. The older non-turbo California does not have this system. It has Bosch motronic with regular knock sensors bolted to the engine block..
     
  25. 360+Volt=Prius

    360+Volt=Prius Formula 3
    Silver Subscribed

    Sep 1, 2013
    1,736
    Western Mass
    Full Name:
    Raimondo
    #50 360+Volt=Prius, May 10, 2017
    Last edited: May 10, 2017
    .
     

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