Hi, Would really appreciate some input on this. I've been trying to figure out why my 328 (1988 1/2 USA model) runs rough and hesitates when hot and also why hot starts are sometimes difficult. I had a look at the wiring to the ECU rear trunk right side this evening for the first time since I bought the car about 6 months ago. What a total mess! I can't believe even Ferrari would leave it like this. Question is can anyone tell me what the two connectors in the photos are for and why they might be disconnected and taped over? Also what is the loose plug for in the second pic? Should it be loose like this? I'm also looking into the relay in pic 3 as a possible cause of my problems although obviously the spagetti wiring is not a confidence booster. Anyone any ideas - much appreciated. Thanks Mark Taiwan / UK Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
I'll have a look at mine. The unplugged multi-pronged harnesses taped over with electrical tape is worrisome. The ECU I believe has a diagnostic port, not sure if this is a port on the actual box or if there's a connection coming from the box plugged into a diagnostic module--that could come into play here. Look at the 328 wiring diagram here. Study it to understand the connections that should be going to the ECU. They will be shown. You can correlate things with the color codes on the wires--learn your italian colors and abbreviations! http://ferrari.jenkins.org/books/
Is the relay with the fuse buzzing when the car's running? If not, replace the fuse and see if that doesn't help. I think the other plugs are connected to the thermocouple and the slow down light circuit. Does your slow down light illuminate briefly at startup?
Tillman and Mike thanks for the responses. I haven't checked the buzzing of the fuse or relay yet but I've ordered a new item from Ricambi anyway as I know these have a reputation for going bad and causing intermittent problems. The slow down light doesn't illuminate or at least I've never noticed it. Took the car up to the main dealers here this morning for something else and it wouldn't re start in their workshops (!) so they have it for now. The head mechanic thought the disconnected plug/socket might be for emissions systems but he didn't check yet. People here have done strange things in the past to deal with emissions testing and homologation - absolute horror stories but thats a whole different thread............! Mike I've copied the wiring diagrams - thanks for the link - wiring is not my strong point I always find these things almost more confusing to refer to but I'll do my best. I thought the diagnostic port is the one on the left hand side member in the engine bay or am I wrong? Thanks for the input though - any more pointers gratefully received. Cheers Mark Taiwan/UK 308 GT4 328 GTS 964 TL
The two taped connections are the male and female connectors that go to the catalytic convertor control unit (#163 on Fig 1 of the wiring diagram), this controls the slow down light. They should be plugged into each other. The control units go bad all the time. Do a search and you will find lots of information on them. It has no effect on the way the car runs. The small black componant that is unplugged is a protection diode (#166 on Fig 1 of the wiring diagram) for the injection system, it should be plugged into the unused wires with the pink/yellow stripe. This goes to the throttle micro-switch and lets the lambda computer know when the throttle is closed. It is an important input. Plug it back in. The fuel injection system has no diagnostic connector. The diagnostic connector on the left side of the engine compartment is for the ignition system. Brian B.
BrianB, Wow thanks a lot - thats really great info - really appreciate it. I imagine the Cat control unit plugs were separated because the control unit went bad as you suggest. If I re connect them will this have any affect on the running of the car or should I just leave them alone? What should happen when I plug in the protection diode as you say? Its clearly been disconnected for some time and the car has been running albeit a bit rough now and then. Thanks for all the responses so far I'll try the fixes and post back. Cheers Mark Taiwan/UK 328 GTS 308 GT4 964 TL
Last thing, which is the cat control unit in the photographs or is this located somewhere else and not on the ECU plate. Thanks Mark Taiwan/UK
As a quick update. Reconnected the male/female connectors for the cat control unit and the other loose wires for the protection diode. The slow down light now comes on at start up although it stayed on for a minute or so the first time then went off. Otherwise the car seems to run more smoothly and start more easily. So far so good. I also made the ecu relay fit better in its socket - not so loose - so I'm sure that helped too. all in all great advice - thankyou very much for the responses. Cheers Mark Taiwan/UK
Hi Mark, I found this picture (US 1988 328) of the FI computer plate for reference. Best, Carl Image Unavailable, Please Login
The Slow Down light should stay on only for about, say, five seconds when first turnign the ignition to the "run" position. A full minute is not "spec." It's possible what the mess you saw was a hack to deal with the slow down light coming on intermittently for whatever reason or something along those lines. Keep an eye on it!
Thanks for the help Carl - many thanks for the picture - now I know what I'm aiming for its a big help. Mike - what are the possible causes of having the slow down light on for longer periods? You mentioned the "cat control unit" going bad but where is that and should I make efforts to repair/replace. I don't want to disconnect the plugs again as I'd prefer to know everything is working as it should. I know there is no problem with the cat itself or the injection/ignition system as its recently had a major "service" at the main dealers. One would think that something like this ought to come up during a major service. Help much appreciated as usual.... Cheers Mark Taiwan/UK
