Hi all, This is my first Ferrari, so apologies if this is a bit of a noob question! Had my '96 F355 GTS manual for about 2 months now. A couple of days ago it felt a bit rough pulling away (almost like carb icing back in the day). Once I pushed through it, though, everything seemed OK. Took it out this morning and it was the same. Did a 30 minute run on country roads and it was great. Parked it up for a couple of hours and now it's worse. Not able to "push through it" any more. Sounds really rough, so just limped it home. On the way home, the "Slow Down" light flickered for a second or two, but didn't stay on. Reading the manual, does this suggest that there's an exhaust problem? Oil pressure & temp, and coolant temp all normal. It had a major service in July this year. Any pointers to avoid a garage trip much appreciated, thanks .
Check ignition wires, spark plugs, fuel pressure and Cat Temp Protection circuitry. It would help you if you can an OBD2 scanner for that car.
Pull the ignition wires from the car. 1) see if there is water in the spark plug holes, 2) measure the impedance, 3) inspect the ends to see if they are good. Pull the spark plugs, 1) read them,
Hi, it sounds more like the wiring harness has been stretched , when the engine was removed . this is a 5,2 right ? I have been working on Ferrari for 31 years now & have seen & fixed this problem many times The car starts & runs ok , but when you drive it & give it some load it starts to cut out , like a rev limiter.
The Slow Down light can only be caused by high cat temperatures (or perceived high cat temperatures due to thermocouple ECU faults). From your description though, it sounds like your initial roughness is appearing before the Slow Down system is triggering any kind of bank shutdown, so the roughness probably isn't due purely to excessive cat temperature, but rather a combustion problem (i.e. fuel/ignition issues). If you can pinpoint the problem to a particular bank that would be helpful. What kinds of tools do you have? spark tester? infrared thermometer? OBD2 reader? I assume you don't have a standard 16 pin OBD2 port under the dash as you're from the UK, so you'll probably have to buy a 3 pin to 16 pin adaptor and plug an OBD2 reader into your Motronic ECU diagnositic plug (behind the driver's seat). Google "Fiat 3 pin OBD adaptor" (either on this subforum or globally).
The other thing you can do is ... bring a laser thermometer with you when you drive. When the stuttering happens, pull over, pop the lid, measure the temperature of the cat converters (L/R) and see which one is running hot.
Harnesses are a bundle in a sheath, I'd be curious to hear how a specific wire in that bundle that causes this gets stretched but not the others, it would be good information to have. Perhaps its a wire pin end at the ECU connection plug?
The wiring bundle for the 355 is very poorly made with thin gauge wires. Added to that the very small hole where the bundle has to squeeze through during an engine out damages the integrity of the wires. After many heating cycles, they go brittle and break when they get tugged in and out of the car. Then, you get to go hunting for which wire no longer makes contact.
Same as the 348? I pulled my engine and the wires practically fell out of the hole before I had a chance to feed them, more than large enough it seemed on 348? But sure of the wires a think with age it becomes a brittle issue for sure. I think I am going to replace both my harnesses.
I was going to recommend a good speech therapist but I suspect it's something else. Sent using FerrariChat.com mobile app
On Ketel's 355, Injector number 2 was on all the time and caused cat to glow hot, shut down the bank. The bad wire was found, cut, rejumped, and it worked correctly.
All the injectors use a common power source and individual earths from ECU pins to control firing. The only thing that would cause an injector to stay on all the time would be the wire from the ECU shorting to earth. Not sure how stretching would cause this. Sounds more like abrasion.
I think the stretch cracked the rubber insulation right at the Ground points inside the harness. But unless we can cut it open, there is no way to be sure. It's fixed, it's gone on to the next owner.
OK, attempting to connect the car up to some sort of diagnostic. Ideally, I would like to be able to use one of the Bluetooth connectors that "just works" with a variety of mobile phone apps. I have a '96 euro car that was originally LHD until converted, so I assume the connector is behind the seat. This is what I found. Is that correct? If so, how do I go about connecting it to something useful please? Image Unavailable, Please Login Image Unavailable, Please Login
It started life as LHD in Germany, but was properly converted to RHD over a decade ago when it came to the UK. Can you see the connector in this footwell shot? Image Unavailable, Please Login
I have a 95 355 and as many others on here have very intelligently (more so than I) posted, the "flickering" slow down light and car intermittently going into what is called "limp mode" is most likely a wiring issue and/or cat temp/ECU issue. For several years I/we (FoD) chased a condition where my 5-8 Check Engine (amber) light would briefly flash and then almost get "cancelled" by a very brief flicker of the red slow down light for the same bank - yet the car ran fine. They swapped ECUs etc. to see if the issue followed and it did not. Finally, after a LOT of digging there was a crimped wire and the overall wiring box was loose - wiggling the wire replicated the condition. New wire/re-solder/tighten the wiring case and wa-la - issue solved. Oh and BTW the darn thing did not throw and OBD codes - Grrr :-( Anyway, LOTS of great diagnostic suggestions on here so good luck but IMHO wiring could be the culprit just from experience. BTW - You might want to check out the Gold Connector Kit from Scuderia Rampante (I can find/send the link) - This will/can solve a LOT of annoying issues with the connectors and wiring that is a known weak spot in 355s (and other older Ferrari's I presume). Good luck - Cheers
Thanks, good info . Can you explain exactly where you found the fragility in the wiring? Locations photos always useful .
The value is in new connectors and tight fit. You can buy the ends and tools from digikey. The material is irrelevant and mixing metals causes galvanic corrosion. I would wager more people make things worse trying to put new ends on who lack experience/skill. The wiring is tight it's not like there is an extra foot to play with per wire. Personally Is just buy a new harness as issues can be the wire brittleness between the ends one spent time crimping possibly making things worse or best case still have same issue. Just a thought. Sent using FerrariChat.com mobile app
Btw you can download the WSM from various links it will guide you on most things. It's a 355... you'll need it and make plenty of use of it. Sent using FerrariChat.com mobile app
Sure - It was in the ECU wiring harness - pics below if helpful - Also, here is the link to Scuderia Rampante and the Gold Connector Kit => https://****************.com/product/gold-connector-kit/ Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
