348 - one bank shutting down

OK, I know this is another boring SLOW DOWN thread but .....

I searched the posts and couldn't find the same collection of symptoms:

I used to get the SLOW DOWN and intermittent loss of 4 cylinders. Sometimes they would cut in again, sometimes only after a longer period of running on four, sometimes only after 2 or 3 restarts.
Main Dealer replaced CAT ECU + Oxy Sensor
That sorted the SLOW DOWN light with intermittent loss of 50% of the engine OK

However:

nearly every day now, 4 Cylinders shut down with no lights at all.
If I then turn off ignition and restart, they always kick back in again and all's well 'til the next day.

It's getting so common now, that I've developed a driving procedure - I just drop the clutch, the engine stalls, I let the clutch come again, engine starts itself and all is well. I don't even have to switch off the ignition.

Any ideas guys?

 

Are you sure the dealer just didnt take out the lights for the slow down. Have you gone through the test codes in the ECU?

 

Yeah, if I look at the bill I got, he must have done more than that! LOL! (Seriously though, the completely erratic, non-resettable, sometimes every 2 miles, sometimes never during 3000 km, SLOW-DOWN was cleared up.)

To be honest, no. Will that help? Even after I've done a running reset as described to get home? Does it store info from the last failures even if they were 'reset'?

Cheers

 

Do all of the lights in the dash come on when you first put the key in? They should all light up.

 

Hadn't really paid that much attention ernie. Will give it a go tomorrow.

 

Yes you need to check the ECU codes. I have had a few codes that caused problems and never once turned on the lights.

Also just for fun, one time I had a fuse bad, which was listed for the gauges, well apparently it went to more then just gauges, because mine did what yours is doing, it would drop down to 4 cly then stall, but would start back up. Anyhow some fuses could cause this even though its unlikely in your situation. check for proper connections on all fuses.


Ben

 

I've just remembered when I was having the real grief initially before it went to the main dealer, sometimes the shutdown was accompanied by a SLOW DOWN light, sometimes it wasn't. I just put that down to a touchy diagnostic system. But it seems that I was having two different overlapping causes. The Dealer fixed the one which was lighting the light it seems, thus leaving me with the second one which doesn't light up.

 

You've got a couple of ECU and fuel pump relays on your passenger footwell fusebox. These relays have metal exoskeletons.

If you see any white/corrosion/flakes on these exterior metal shells (of those relays), then you've got a relay that is just about to go bad. As you can imagine, a bad ECU relay or fuel pump relay is going to cause you to intermittently lose half of your 348's engine.

If you *don't* see any external signs of a bad relay, then pull each fuel pump and ECU relay and examine the metal contacts. Just before they overheat and die, those metal contacts begin to take on a blue colored patina.

Likewise, it doesn't hurt to scan all of your relays. For your black plastic relays, you may see burn marks on the outside black plastic shell, or blue metal contact points.

Replace all such relays, naturally.

FYI, a bad ECU relay will prevent you from seeing the check engine light on that ECU side...but the SlowDown light (if memory serves) is still powered by the exhaust ECU (so you aren't in that sort of danger).

Also, your Euro version may not have the Motronic's check engine lights enabled.

 

OK, will check too. Have already got Stabilant 22 at the ready!

-13°C in the garage last night though!

Drew

 

I put Stabilant 22a on all of my metal relay contact points and fuse points. I put it on all of my ECU pins/wiring harness connections. I put it on all of my common ground points.

There's just no downside to having better electrical current and electronic data connections.

 

ernie, have just been round to the (freezing) garage and turned the ignition on. Yes, the SLOW DOWN lights both illuminate for a few seconds then extinguish.

I remember there were a few good posts on the procedure for reading out the ECU codes but can´t find them with a search at the moment. I found some info on what the codes mean - just couldn´t find the post with the procedure.

Drew

 

http://webpages.charter.net/aircover/348/1994Ferrari348Spider.html#ECUcodes

 

Thanks for the link. Not so sure if the procedure will work now though as mine is a Euro version and the Check Engine lights are not enabled. I´ll go through the procedure though - perhaps they work for diagnostic purposes only. As they don´t illuminate during start-up, I can´t simply determine if they´re even fitted with bulbs.

I know during the original bad cut-out problems of post #1 the dealer said he wasn´t getting any error codes indicating a malfunction. At that time, he assumed it was a heat related problem due to a sports muffler. However, I´ve now exchanged that for a standard one.

 

Do your relays look alright?

 

They´re on the list of things to check still. Unfortunately, I work in France and the car´s in a lock-up in Germany. I only have the possibility to pass by the garage between flights and business meetings at the moment. It´s freezing in Germany so I can´t do much until the weather clears unless I want to get frostbite!

So I´m concentrating on things I can check at the moment whilst wearing gloves!

 

If only you had said you were in the army and the car was in a depot in England you could have solved the Ebay scam mystery!
BT