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Persistant CEL and misfire - 360

Discussion in 'Technical Q&A' started by Gary(SF), Aug 9, 2004.

  1. Gary(SF)

    Gary(SF) F1 Rookie

    Oct 13, 2003
    3,637
    Los Altos Hills, CA
    Full Name:
    Gary B.
    2004 360, 2700 mi., stock except for Capristo level 2 installed at 1500 mi. What a pain in the butt, the timing could not be worse with Concorso and the Historics, FNA event, etc coming up. About a month ago (maybe 2300 mi) I got a CEL, engine was running fine. After checking gas cap, etc, I gave it a few weeks to maybe fix itself (ever the optimist) and when it didn't I drove up to FoSF to have them reset the light. I noticed some slight intermittent hesitation/roughness as I drove through SF on the way to the dealer, but it was very minor. They reset light, which came back on during the drive home, roughness now slightly more apparent. I called roadside the next day and they picked up the car (last Wed) and flatbedded it to FoSF. After several days of diagnostics, they claimed they found the problem, a timing sensor. Trucked it back to me today, I drove the car and within 3 miles the roughness and hesitation was back. Within 8 miles I had the CEL, and the roughness was definitely worse, really began running bad, I was wondering if I was going to get home. Called FoSF, they are mystified also, they drove it 3 cycles after replacing the timing sensor with no problems. Back it goes tomorrow, I told them I have to have a perfectly running car by Thursday and they swear they'll make it happen. Man, I hope so, I've been looking forward to these upcoming events for a long time. Anyone have any similar stories?

    Gary
     
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  3. Rifledriver

    Rifledriver Two Time F1 World Champ

    Apr 29, 2004
    27,086
    Austin TX
    Full Name:
    Brian Crall
    As of 1 year ago (when I left Ferrari) they could still not explain what constituted a "cycle". I had it explained to me (so did Dave Helms) by the man at Ferrari that spoke to them that Bosch would not or could not share the information. One of the reps in the class Dave and I were in came up with the supposed cycle info but during that class upon examining it we realized that the set of circumstances required for his cycle could not happen. I hope this information is not what is being used. The sys requires that on many components several malfunctions have to happen to set the CEL. That is why the cycle information was so important to us. With out it it is hard to confirm a repair. The SD2 only tells you what parts of the engine management sys are not operating as intended. But you need to determine, is that cause, or effect? It is a method to gather information and does not point to a specific part that is bad. The information has to be interpreted. Did they by chance share with you the SD2 print out? It would be interesting to see the list of errors.
     
  4. thomas_b

    thomas_b Formula Junior

    Sep 15, 2003
    765
    Do you have the related error code that comes with the CEL?

    One of the problems I had was related to the misfire detection – unfortunately I can not remember the code; I think it was P0360 Multiple Misfiring Detection or something similar

    The 360 have a problem with false misfire detection – detection is accomplished by monitoring the movement of teeth on the flywheel – sensor is called “Angular Velocity Sensor” but is also used for timing purposes (TDC) – misfiring is detected by changing velocity, i.e. oscillation

    Assuming that you brake very hard or go over very rough roads the change in traction causes changes in load and corresponding changes in “angular velocity”, i.e. it may fake a misfire behavior

    Car uses the ABS sensors to compute a road bed roughness signal (difference in wheel speed front/rear) that is fed into the ECUs to tell it when it should ignore the misfire detection signal

    The mechanism is mandated by emission rules - you got to love the OBDII stuff

    I did get the misfire error when I did bed my brakes and brakes very hard and once when I run over railroad tracks – the CEL however did only flash and there haven’t been any negative effects such as loss of power – only an error in one of the ECUs

    F stated that the 360 is sensitive to misfire detection as explained above – specific cars may show this behavior because the combination of sensors and ECUs might just be at the edge of the detection tolerance – in my case the CS with its stiffer suspension and better brakes

    Clearly (and hopefully) the dealer does not drive the **** out of your car so they might not see the problem

    anyhow I feel for you ....
     
  5. Rifledriver

    Rifledriver Two Time F1 World Champ

    Apr 29, 2004
    27,086
    Austin TX
    Full Name:
    Brian Crall
    You are correct, the mult misfire is quite common, so much so we usually ignore it unless it fits in to the other symptoms. The Ferrari shops and dealers don't use the P codes. The SD2 gives a much greater and usually more specific type of info. Those are generally only used by people that use generic scanners and the SD2 is better at gathering info.
     
  6. Gary(SF)

    Gary(SF) F1 Rookie

    Oct 13, 2003
    3,637
    Los Altos Hills, CA
    Full Name:
    Gary B.
    I'll ask them tomorrow for a printout. I haven't been driving over any rough roads or high loads at all lately. The misfire is very real and seems to develop at low speeds and kind of clears up at higher speeds and revs. The printout should be interesting, I'll post it when I get it.

    Gary
     
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  8. Gary(SF)

    Gary(SF) F1 Rookie

    Oct 13, 2003
    3,637
    Los Altos Hills, CA
    Full Name:
    Gary B.
    Well, I just heard from Kevin at FoSF, and he says they found a loose ground wire to the O2 sensor, causing a full-rich condition when it broke contact. That would explain the symptoms of intermittently running poorly at idle and low revs and seeming to clear up at higher engine speeds. I hope they got it this time. He said they isolated the wire bundle and were able to induce the misfire by moving the ground wire around. Fingers and toes crossed...

    Gary
     
  9. csteve

    csteve Karting

    May 6, 2006
    171
    hong kong
    Full Name:
    steve chang
    My CEL (engine misfire) went on last week and went off by itself a week later (today). Has that ever happened to you guys?
     
  10. Ingpr

    Ingpr F1 Rookie

    Jun 30, 2009
    2,577
    PR
    Full Name:
    David
    Hi Gary,
    Did you solved your problem by changing the u2 sensors?

    Do anyone can tell me if I can diagnose a bad ignition coil or wire by using the sd2/sd3?

    David
     
  11. Dr_ferrari

    Dr_ferrari Formula 3
    Professional Ferrari Technician Consultant

    Nov 2, 2003
    1,064
    Pocono Sportscar
    Full Name:
    Jim McGee


    Sounds like a possible intake manifold gasket leak. see if you can determine what cylinder is misfiring and check the intake manifold to cylinder head gasket. they tend to weaken and get sucked in.

    Regards, Jim
     
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  13. Ingpr

    Ingpr F1 Rookie

    Jun 30, 2009
    2,577
    PR
    Full Name:
    David
    Jim,
    I have a similar problem. I did a vacuum pressure test. It have a solid reading of 22 in hg even whe I acelerate the car. Compresion test was 180 on all the cylinders. Fuel pressure is between 50&60 psi. Fuel filter is clean. Sparks are new.

    The only parts left to diagnose is the wiring and the coils. That is why I'm checking if the sd2 can tell so.
    A bad O2 sensor sounds logical since my cell light only pops up when I acelerate the car.
     

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