Howdy I'm new to Ferrari ownership having just purchased a 328 GTS with 75,000 kms on the clock a couple of weeks ago. The car was subjected to an inspection and road test by the local Ferrari dealer and service agent and there were a few niggles but no mention of a missfire. While out driving the other day I decided to try the higher portions of the rev range and when the engine got to just over 6000 rpm there was a significant missfire that felt like a rev limiter. It was consistently present at just over 6000 rpm. These things are supposed to rev to 7700 rpm aren't they? The car has had a couple of plug leads replaced within the last 12 months ..... could this missfire be due to more plug leads failing?? I'll take it to a good mechanic who knows this particular car, but would like to try to understand the problem, or likely problem, first. Any ideas?? Steve
Most definitely could be bad wires, or plug extenders. Also, it has been shown that incorrectly installed wires in the distributor cap, can also cause a miss.
Basic troubleshooting. If a "couple" leads needed replacing, you should replace them all! Try that first. Missing at high RPM's is a common symptom of points bounce. Do you run points? (I have no idea on 328's). The other thing that immediately comes to mind is fuel flow. If you have a partial blockage or weak pump, it will start making itself known at high RPM's and can seem like you've hit a patch of glue. Replace the fuel filter next and see if that helps. If not, you'll need to pump gas into a bucket or something to see if the line is clear and you're getting whatever flow 328's need. Long shot is exhaust blockage; but with cats it may be more likely than a long shot. I have no idea how to check this; I don't have 'em. Check electrical and fuel filter first. Ken
My inital thoughts are plug leads .... if some are bad others will surely follow shortly. IMO previous owner should have replaced them all ... $$$ may have been an issue. AFAIK the 328 has no points, but used solid state ignition modules ... might be wrong though, I'm still at the "oh my god, that's a Ferrari in my garage" stage .... haven't pulled the car apart yet. FWIW it didn't feel like a fuelling problem ... wasn't soft. It felt like a hard rev limiter .... several cylinders cut. I was almost convinced that I was hitting the cars rev limiter at just over 6000 rpm. Great ideas guys, keep 'em coming. Steve
The other thing you want to check is the condition of the wires for the crank position sensors. Make sure that they are clean and connected properly. You will also want to look under the rubber boots that cover the conectors, to check the condition of the wires. You may find a frayed or broken wire that is the cause of the misfire. It can be making enough contact to carry the signal at the lower rpm's but as the engine speed gets over a certain rpm the wire can't handle the signal. Also have a look at the connections for the fuel injection, and if you have one the cam sensor.
I think you actually do have a rev limiter. The ferrari rev counters and speedos aren't the most accurate. Could it be that you actually are doing 7500 rpm? Perhaps you can cross check with the speedo, or better still a GPS.
No rev limiter on a 328 (at least from the factory). But yes, do check the calibration of your tach. The 3.2 engined cars are notorious for low reading tachs. Any speedometer shop that services Ferraris will be well versed in this common ailment. Dave
This car was actually sold to a customer in Germany originally. He imported it into New Zealand thru Australia in the early 90s. Possible it has a rev limiter. I had wondered if the tacho could have been reading way low ..... something to check out I guess. Steve
