456 6speed 1995 broken down!

I thought that I'd take my wife away for a nice weekend together. I had been dealing with a blocked rear brake pipe on the 456 this week so she was slightly wary when I said that we'd take the Ferrari!

After about an hour of easy driving I noticed an occasional 'stutter' as well as the orange "Engine warning light 7-12". It would disappear then return randomly. I thought that it was getting worse as we pulled into the restaurant for lunch yesterday. I called a Ferrari trained mechanic who thought that it might be the MAF sensor or O2 sensor on that bank of cylinders, otherwise it could be an injector. But his garage was some distance away so I called the AA recovery service.

The AA man arrived and admitted that he'd never actually seen or worked on a Ferrari engine before. But we looked for anything that might have become disconnected. He did notice that one of the spark plug leads (the top part with the Ferrari logo) was a little distorter. I admitted that I'd used pliers to remove the leads last summer when I changed the spark plugs last summer and that I had damaged the top of that lead. However, the car had been running perfectly since then with this lead in place.

I called a friend who lives near the restaurant and he told me about a local mechanic who has owned several Ferraris and works on Ferraris and Maseratis. It was only 2 miles to the garage so I asked the AA man to follow me to the local garage. The car had been sitting for 90 minutes and it ran perfectly on the 2 mile journey with no misfires or warnings.

The suggested local mechanic knew way more about the engine, thank goodness. The AA told him about the plug lead but he replied that one faulty plug lead would not be enough to trip the engine light. His suggestion was cam sensors. He said that we could swap the cam sensors to see if the issue moves to the other bank.

The car is not going to be looked at until next week and one issue is that the problem is intermittent. Any ideas over the weekend would be very welcome.

 

I haven't seen a test button in the driver's footwell. This procedure does seem like a dark art!
I'm still very interested to hear of any armchair diagnosis suggestions.

 

That's really helpful, thank you. I've heard that the spark plug wires are very expensive. Any idea what he paid?

 

But wouldn't I get a 7-12 slow down light if the cat gets too hot?
I only got 7-12 Check engine warning.

 

I’ve just heard from the garage: “It’s a misfire and I’ve ordered a set of leads which will arrive on Friday “.

I’m going to keep the old leads for spares.
I stupidly used pliers to pull off the leads when I changed the spark plugs last year. I slightly misshaped one of the leads (underneath the Ferrari logo) on the bank with the misfire. Is there anyway to repair that connection so that I can have a spare set of 12 for emergencies. Or does everyone always replace them as new sets of 6?

 

Ferrari classic parts sent the wrong set of leads last week.

Just re-ordering and the price for a set of 12 with harnesses is £2,000!
As only one lead is damaged is there a solution to either repair or replace the damaged end on the lead?

Someone suggested that a member on here sells individual leads. Anyone know their name please?

 

It was a broken spark plug lead, where it connects to the rubber boot. I guess that connection suffered as the car became hot.

The mechanic ended up cutting the rubber boot open and repaired the broken core by soldering it to the connection in the boot. This was not his preferred option, but it did get my car home while I sourced new leads.

Having tried to buy a whole new set with the plastic mounting harness I discovered that all of the sets available in the UK are aftermarket sets without the Ferrari logo on the top of the boots. Even the sets at £2,000 did not have the logo.

I have bought 4 original spark plug boots from a Ferrari owner (with logos) so that I can just replace the one repaired lead (although the fix is working perfectly). I can source the lead from a member on here and add one of the new boots which will arrive in the next few days.

Hopefully I've managed to save £2,000 and retain the original look of the engine without aftermarket parts.