P0300 - Multiple Misfire issues

I had the same issue with my 360 last year. Drove me nuts but was slightly different as it usually only happened when warm. It sometimes did it when cold but switching off and restarting usually cured it. I'm still unsure of the cause but I am pretty certain its actually the ecus that are causing the bank to shut down rather than anything mechanical. I suspect is actually where the car is trying to put itself into limp mode. I persisted with the car and eventually it got worse to where it would actually put itself into limp mode each time rather than just throw a code. My car is fine now it seems and while I am not 100% sure what fixed it I would recommend using techron fuel cleaner, cleaning the pedal assembly connections, cleaning air filters and making sure the running in procedure is followed correctly after resetting. I did all of these and it got better although it may also be related to my ecus burning out as this happened around the same time. This may have been a coincidence though. I had the ecus repaired for less than £100 a pop here in the uk so it might be worth getting that done too to rule it out. Check my previous posts. As for a recommendation of a garage to help if you are really stuck try roger at the ferrari centre maidstone. He does my annuals and is a top guy, even worth me making the trip all the way from Cardiff each time.

Message me if I can help further. Good luck though and please post here if you get it sorted. It drove me nuts for months and while I'm still not too sure why its fixed, it would be good to know for others.

 

Steady 0.09V on the O2 sensor is not good at all. The value refers to rich fuel condition and causes ECU to reduce the amount of fuel, and thats why the misfires can occur. But for you is important to source the root cause of this. When not MAFs, intake gaskets, ECUs, O2 sensors and other things swapping will not help, I would try to check the spark plug gaps between electrodes. Just the smaller gap on one SP can cause bad combustion without misfire putting a lot of unburnt fuel into exhaust and fooling the sensor. The same with fuel injectors, if one gives more fuel during the injection pulse, the same situation will occur and will affect the whole bank...

 

any one know how to interpret these LH and RH ecu fuel trims?
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would you elaborate on what difference is 3mm?

sleeves? valves?

What exactly is 3mm difference?

 

Personally I would NOT attempt repair on the sleeves. They are lined w Nickasil and after boring would need recoating. Where will you find oversized pistons for the larger bore? The nicking process is very hard to get right although many claim they can do it.
Personally - I would find a low mileage street engine from a breaker and avoid attempting to re-engineer a very expensive engine. Rebuilding with stock part =yes but as you found very expensive, replacement used engine =yes, rebuild with aftermarket parts=NO, not worth the many headaches. Just my 2 cents.

 

If you can get Mahle to speak w you, they make the pistons & sleeves, I know a few people looking for a reasonable replacement part. If you say the word Ferrari, I think you'll find the conversation over- they are the OEM supplier so you know where their loyalty lays.

 

hi, i have no clue about these things but with my rudimentary knowledge, isn't he just going to replace the damaged sleeve with a new OEM one and a new OEM piston and call it a day?

 

Probably means 0.3mm out or 12 thou to Americans. In chevy terms now you gotta bore out 20 over.


Crazy thing is how valves bent. Likely not full diangosis when gasket went causing more damage seen today.