On those motors the cam timing doesn't have to be off a great deal to cause those problems. That is why the procedure is to degree in the cams every time and not to just align the marks. On a 1 1/2 inch dia shaft (where the marks are) 2 or 3 degrees isn't enough to see but it is enough to cause a problem. The tolerance is +/- 1 degree from spec. It is one of the reasons that timing belts are expensive to replace. Many people just slide new belts on, out of ten times you will get away with it maybe 8 the other two you get bit. The only way I see that happening in this case though (to effect both banks) is if TDC was not properly arrived at. Cam timing issues are a very big problem with modern Ferrari's (since the 348/TR) for that reason and it is compounded by the fact that is a very commonly performed procedure with these cars so the exposure is high. At Ferrari training schools proper cam timing is drilled into us as is suspecting it when a problem occures. At the 360 school at the factory the only hands on thing that was required of every student (observed by an engineer from Ferrari) was to perform a cam timing operation on a motor in the class room. Several of the students in my class (all experienced Ferrari mechanics) had to do it more than once before the F man was satisfied. In that same class it became known to many of us that Ferrari defines TDC differently than the rest of the industry.
One of the things I forgot to say was that as noted by tbakowsky the parameters for operation of the O2's is very narrow (some early cars too narrow) and for cam timing to get those out of parameters is far less than what is required to cause a noticeable running problem. It is however possible to diagnose with an exhaust analyzer if you know what to look for.
I have heard anecdotally (sp.?) that Ferraris are particularly sensitive to the addivives in Chevron gasoline (Techron, I believe it is called) and that it has frequently killed modern Ferrari O2 sensors. I used to use Chevron alot...and I have had all 4 O2 sensors in my 550 go out (not at the same time). However, I stopped using Chevron 2 years ago...and have had no problems since. I dunno if there is any connection...or if the anecdotal evidence from others is true...but FWIW.
Thanks for advice Maranelloman. I pretty much only use high test Shell so I guess I am lucky on that count. They replaced two airflow meters ($1370.00) and two front O2 sensors ($330.00) so far. Now they are going to drive it and see if the light comes on again. Labor charges they are trying to figure out and will tell me tomorrow how much is mine. The original dealer in Boston is now getting involved maybe and FNA is talking with the two dealers to see who is paying for what. I just hope the car works first. Thanks again for the help and I will keep updating this until I fnd out what really is malfuntioning. Keep up the great political posts Maranelloman, I love them. gary
It's a minor difference but can be important when you consider how small the tolerances are. In every other vehicle or enviornment I have been exposed to TDC is defined and measured as the point halfway between when the piston arrives at its highest position and when the piston leaves its highest position, or the middle of the dwell period. Ferrari defines TDC as the exact point at which the piston arrives at it's highest position when the motor is turned in it's direction of rotation, and depending on a variety of variables those two places can be a couple of degrees different.
Well, as Diablo posted earlier in reference to a campaign about the motronic contols and having a problem with some, FNA and Central Florida is not sure if that is the problem, but they are pulling the computers out of the car and sending them to FNA where they will remap and upgrade the ecu's. They replaced two front O2 sensors and two air flow meters and the engine check light is off now, but they also want to do this even though my car falls outside the time frame of cars effected by this. Even though it may take another week, I am glad they are working hard at trying to get the car right. I feel Central Forida and FNA have really been trying to help. The next step the will be to recheck the timing if the light still continues to come on again. How hard is it to check the timing?
To do a proper job, intake manifold off, both valve covers off, all belt covers off, about a day give or take. This is very important: I installed lots of those remapped ecu's from FNA. Very high failure rate, even had one set a car on fire. Cat fire. Diplomatically ask them do an SD1 test after inst. and check all parameters. Special attention should be given to the ignition timing, I know it's not adjustable but the data is shown. I have had those remapped ecu's start at 45 deg btdc. They should also pay some attention to the upstream and down stream O2 data, seen problems there too. IIRC I averaged about a 50% failure rate on those stupid things. I got to the point that I was doing before and after print outs so I could prove that it was the ecu's and not another component failure. I also started writing "NFG" on them so they would quit sending the same ones back. I was never sure if they were remapping defective ecu's or if remapping was screwing them up. I hope it has been long enough since that was being done that they remap yours. At least that will eliminate one possibility.
Well. After relpacing two front O2 sensors the car appeared to be fixed, but FNA wanted to upgrade the ECU software just to make sure the problem was not stemming from faulty software. FNA tok my ECU's and remapped the software. Now the car's idle jumped up to 1600 rpm's and stays there. So now, FNA wants the ECU's again to remap them again with its original software. The saga continues.
I thought I would let anyone interested know that I finally resolved the engine check light. After reprogramming the ecu's twice which did not work, FNA finally put two new ecu's in the car (under warranty) and it is all fixed. Finally after one month. FNA was really great in working with Central Florida. gary
Funny when the factory engnr. did not want to discuss the TDC thing at all! Brian, you brought a smile to my face remembering the ecu replacements! We did a dance around each car, and figured that gave them a better chance to survive! I ended up with a number of the 550's that puked all 4 O2's at the same time. One was tracked back to the car being detailed the same day, picking up the glaze from buffing the hood. After it happened twice, I knew I found the problem on that car. Make sure the hood vent to the air filters is taped off when detailing. Remove the green weatherstrip from the weatherpac plugs at the end of the O2 wires. The O2 draws ambiant air up the wire under the insulation to use as a base sample. Bosch had problems here as the insulation was apparently too good and cut out the sample air. Worked on around 4 other cars. Spent a great deal of time with an engnr. from Bosch before he gave that one up! Dave
Good to hear. FNA must have a better guy out there than they gave us after John Amette left. Sounds like they tried very hard to get things right.
