After my recent attempt to pick up the F355 where it again exhibited the same ‘chugging’ I had before, Ferrari have provided their updated troubleshooting report:

So far here is the sequence of events since you dropped the car back:

1. You arrived back, switched the vehicle off, I restarted it and witnessed the issue. That afternoon it was parked up until the technicians got back onto it.
2. The technician started cold, all ok. Ran until hot, restarted, all ok. Road tested, came back and switched it off again, restarted, all ok.
3. The next day we tried again, this time emulating exactly what you did. Started it up, brought it to the front car park, drove out, stopped at a local fuel station, added around 15-20L, restarted, all ok. Drove back to the workshop, restarted again, all ok.

It seems to have been pretty intermittent, however the only error code logged is the same that we have originally seen relating to the crank position. We carried out a number of tests again including vacuum testing and smoke testing the intake etc, all checked out ok. We also connected an oscilloscope to the crank position sensor and checked the signal for any irregularities, found none.

At this stage I thought we should be re-verifying where were at regarding the injectors.

5. We carried out a leakage test in the car again, and found 1 bank holding pressure, and 1 bank dropping slowly in pressure.

6. We used a borescope to investigate into the cylinders and see if any have more/ abnormal wetness indicating leakage of the injectors. In this way we were able to identify injector number 2 to be the worst. However I asked the technicians to remove all 8 injectors from the engine again, connect to our bench tester, and to carry out the pressure testing again on the bench,

We are still at this stage currently. However myself and the technicians are believing that the issue I guess has not been completely rectified, but become much better – much like the condition report of the injectors themselves.

I would say next steps would be to begin the hunt for used injectors and have them checked and serviced. However at this current time I cannot confirm if we are looking for just 1, or perhaps multiple. I should have this information for you next week.

Let’s see what next week brings eh? It looks like a good set of second hand injectors are the next step as new replacement injectors for the F355 are not made by the original supplier (Bosch), thus second hand ones are my only option it seems.