A couple issues with my new-to-me F355

Finally @Portofino you state this misinformation came from your tech and you are based (sometimes?) in Yorkshire. Perhaps you would share the name of the garage so that it can be avoided by other folk sometimes based in Yorkshire, like me!

 

@Julia If you have no cats, unplug the cat ECUs and take the slow down bulb out of the dash.

 

He does understand this, Steve, but he theorised (or his tech did) that a MAF issue (or other single sensor sensor issue) on a 5.2 might cause an overtemp (through wrong fuel mixture commands) on both banks, causing both banks to shut down (which he believes is illegal in the USA).

Before we condemn his tech, Portofino has already stated that there was a remote possibility that he may have misunderstood what his tech was saying.

 

See post #35 which accurately interpreted what I was try to get across .

In simple terms
“A very experienced tech informed me on the 5.2 cars situations can and do arise whereby they loose spark ( for what ever reason ) but continue to inject fuel , while the bank is operational .This I think can occur on one jug or more .”

Obviously this is when there’s a malfunction of some form , be it components or wiring issues , ECU brain farts .

Then there’s the U.K. EU modal variation with US - this can’t be ruled out leading to different experiences by the techs both sides of the pond .

Maybe with the 5.2 s as I said earlier they are a slower out of the blocks cutting the fuel ?

I have always suggested buying a cheap IR gun running these cars , both 2.7 / 5.2 and use it , if you have OEM , stock car and a flickering SDL .

Tech was London based FWIW . Better anonymous.

 

The bottom line is that if you lose spark on one or more cylinders fuel will be cut off if, and only if, the cat temperature monitoring system senses an over heated condition. There are no other provisions to cut off fuel. 2.7 or 5.2, doesn't matter which.

The other thing is that running rich (with full spark) won't typically (if ever) result in elevated exhaust temps because under a rich condition there is no O2 left in the exhaust and therefore no way the extra fuel can ignite. Furthermore, running rich generally results in lower exhaust temperatures to start with.

Finally, @Julia, don't disconnect the cat ECU and remove the bulb from the dash. I wouldn't do that to a Toyota much less a Ferrari. Do the right thing and find the problem and fix it.

 

You will feel it through your arse though and should have the car recovered if it's not running on 8 cylinders, or if you're completely stuck, disconnect the injectors on the affected cylinders.

I suggested this ONLY if there are no cats fitted.

 

Yes, an option if you know which cylinders were the problem.

I realize that was the case. I just don't believe in band aids.

 

Congrats on the beautiful car!

 

Yay!

It's times like this when I'm glad I have an F355 Challenge. I get CHECK ENGINE lights that come on if I'm idling for more than a minute and go off when I get out on the track. They come on and go off within ten seconds of each other.

That's normal for my car which has gutted catalytic converters and has had its rev limiter raised to 9,000 RPM. Air/fuel mixture was set rich at idle.

I disregard those check engine lights and consider my engine banks "synchronized" when lights come on and go off within 10 seconds of each other.

Barry

 

Some day people will listen to me.

Post #6.

Glad to hear all is good, for now.

 

Julia,

John is correct about cleaning connectors.

Our cars are getting old. Wurth Contact Cleaner OL is your friend...


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I heard good reports on here about this stuff and used it on my new to me ( Dec ) 348 exhausts ECU s + every other contact on the two fuse boards footwell + trunk inc relays + the others in the engine compartment eg the MAF s etc .

But the simple removing and replacing does scape off corrosion .

https://www.wurthusa.com/Chemical-Product/Cleaning-and-Care/Electronics/Stabilant-22A-Electrical-Contact-Enhancer-15-ml/p/0893622?srsltid=AfmBOopqqe6deNDVzODliPb243R_Ff_HhMWm5LA7fIiYxdnhKF_BpbOt

 

Easy fix! When I did my major, I used contact cleaner on all of the connectors and then put a dab of dielectric grease in to prevent corrosion.

 

Yes!