car was running fine on the highway and all of a sudden engine started to slightly misfire which got worse in the next 10/20 minutes. Appeared that the alternator was not charging but battery light did not come on. next day, fixed alternator and charged battery. now the problem is that even after several 10 minutes ECU relearning attempts the engine keeps on misfiring. first only on half load, but it got worse and now even at idling and after new ECU relearning, after battery disconnection. lots of smoke coming out of exhaust which smells like unburned fuel. not burned oil is it likely a coil pack going bad or worse? still have to check spark plugs etc. have to decide tomorrow to have the car towed back to my home or the ferrari dealer.
I seem to recall a thread recently about misfires. It turned out to be the spark plug wires. The owner fired up the car in a dark garage and observed blue arcing across the wires. New wires and all was good.... Worth a try maybe?
at last attempt the car was smoking so badly. but it was a fuel smell. no engine light came on. So I don't really want to start my car again to prevent cylinder wash and damaging the liner.
the engine ECU light goes off when engine starts and runs. engine was only misfiring at partial load and no misfire at full load. now with the unburned smoking fuel, still no engine light but ran it only for a short time. So to me I don't think it is mechanical like piston rings or valves otherwise it would be a great coincidence after the low battery voltage and jumpstarting the car. that's why I am guessing it would be the coil pack or maybe coil pack control unit. car is hopefully getting towed back today so I can start pulling the plugs to determine engine bank to start with.
That was me posting about 2 weeks ago about the misfires. It sounds like your situation is much worse. I only had some stuttering. No unburned, smoking fuel. Did you have the battery tested, or did you just charge it? If not, maybe have it load tested.
No solution yet. Battery now fully charged. Changed one of the coil packs. All old original HT wires measure 6K ohm, cleaned connectors. Left the HT wires hanging loose. Car still running bad so stopped engine after 30 secs and pulled the plugs. At least one of the plugs was wet. I already order new HT wires but they have not arrived yet. I hope the problem is the wires and not the ECU. The problem started with intermittent missfire so I doubt it is a fuel injector at this stage. Can HT wires go very bad within an hour of engine operation as there was absolutely no problem before the battery went down on the highway?
Well, I was hoping that new HT leads would sort the problem. Unfortunately not. Started the car, running straight away on 7 cilinders, let it run for 30 secs. Pulled the plugs and again, same plug number 3 wet. ( new plug) So a bit stressed now. Tomorrow I am going to do a compression test but car was running super fine 50 miles ago so I cant imagine the cpmpression went down that quick. The I will pull the injectors and get them cleaned out because the one might stay open. So tomorrow another day.
Check your coil packs, maybe swap them side to side to see if the problem goes to the other side you found it Check and clean connections on the injectors also
All done already and installed new coil packs, new leads, new plugs. plug no3 turns wet almost immediately after starting engine.
Hi there, I ran a quick google search and found a post on the Club Scuderia site, not sure if you can open it as you may need to be a member. It is quick to create an account, but this may help as this fellow had misfires and wet plugs. You probably want to refrain from starting her, at least till you get a little more data. F355 misfiring...
Ok, yes do a compression see where your at. Sounds like you been down this road before. Lets hope for the best here
I read that too, I hope to do a compression test later today. I doubt it is a leaking valve, as the problem got from nothing to bad within 60 miles together with the alternator going down. There is absolutely no sign of Oil residue on the plugs.
Problem sorted. Problem appeared to be a cut in the wiring loom at bulkhead penetration towards injector no 3 which got grounded and thus left injector stuck open. At least the RH catalytic converter got a good wash of fuel!
it is at the bulkhead penetration for the wiring loom of the M5.2 towards the engine I suggest everybody with a M5.2 to check the penetration. Mine did not have a grommet to protect the cabling. I cut a rubber vacuum line open in length and put it over the edge of the penetration to protect the cables.
