F355 Cylinders 5-8 cutting out

the things that make me think it could be a sensor is because if you test 4 cylinders alone (unpluging ingntion coil) you can compare 1to 4 and they dont run better than 4 to 8 so I think of a common part for the 8 cylinders.
on the flywheel puley there are 2 sensors, I dont know if there is one for each bank of 4 cylinders or if each one have a special mission.
I was thinking too about changig spark plugs but they have only 12000km...
Im lost !

 

You could have a bad fuel pressure regulator?

 

? did not thought abaout it ? maybe !
and the car could run well after 3000 rpm with sutch a problem ?

 

Dear fana355france,
My 355 sounds the same as yours, what was it? pleeease....

 

see: SRI's Gold Pin Connector Kit.

It worked for me and my 1995 456 GT.

http://www.ferrarichat.com/forum/technical-q/312756-sri-gold-connector-pin-kit-strikes-gold.html

 

You are throwing in a towel if you just go with the SRI....you have concluded that you have no idea what the problem is, and you are blaming it on an unidentified connection.

If his problem is the ecu or any sensor in the car, the Sri kit will do nothing. I believe this is a shot in the dark at best.

 

The CEL's and Slow Down lights that plagued my car have totally ceased, and I had tried troubleshooting the usual suspects beforehand.

But SRI also did a lot of other work: e.g., the fuse box was burnt / fried, so Dave designed, fabricated, and installed a new, upgraded replacement.

The car is now delightful.

 

Hi, I'm new to Ferrarichat and was promoted to join because of this "5/8 slow down" red warning light coming on and off on my LHD 1995 355 Berlinetta. This light has been coming on and off for years (normally comes on when I first start up and doesn't go off until the engine warms up - about 5-10Km down the road). Usually it then stays off for the drive.But on my last drive it's been coming on and off intermitantly during the entire drive and I've also experienced intermitant loss of power for the first time - bit tricky if it happens on hill in a traffic jam. I don't drive hard so I don't think overheating is the issue here. My gut tells me it's a faulty thermostatic issue but I've not got any experience locating the components mentioned in this chat. Time to get some experience now. I like the idea of swapping over the CAT ECU as AZLambo did. Is this a quick job and can anyone advise how best to locate and recognise these parts. Many thanks in advance for any help offered. Peter.

 

This is a 5.2 car, Peter, but should be in a similar location behind the struts in the engine bay.

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Two connectors, two fasteners. If the fault doesn't swap, try replacing a thermocouple.

https://www.eurospares.co.uk/parts/ferrari/355-27-motronic/exhausts/exhaust-system-40970

Aftermarket components are available from Technistrada.com (at much cheaper prices) if you're not worried about originality.