85 Mondial

Sounds like what was happening to me, without the slow down light problem. When I bought mine, it was running like a fine tuned violin; then it would be rough at random. It turned out to be a broken spark plug cable that I found during my major.

Just a thought.

 

Probably as simple as this. The spark plug extenders are also notorious for doing this as well. Look for a little black 2mm hole on the side of the extender. That's a weak spot where they short/arc. Also the coil ignition modules can go wacko intermittently and screw up an entire bank of cylinder firing, possibly causing the symptoms you describe, including the slow down light.

 

My slow down light started to flicker on and off, then stayed on at times when I first got my car 2 years ago. At first, I would stop the car, take a look at the cats for over heating glowing red, nothing. All normal, not even loss of power. So it was a false reading from the thermocoupler. I traced it from the cat, turns out the wire was rubbing against the sharp metal edge right to the wiring and would cause a flickering. I bought some thermo tape, wrapped the thermocoupler wiring from top to bottom and the light problem went away. It was a cheap and easy fix.

Check what the fellas have suggested above for the rough running in your car, but it could be due to the ignition coils starting to crap out, that would result in gas getting into the exhaust, causing temperatures getting too hot in the cat.. thus the slow down light and the drop in power. Also, the O2 sensor may need to be changed as well but I would start replacing less expensive parts before you spend thousands on a new ECU.

Bosch O2 sensor=~$50
Thermocoupler wire=~$250
Coils Ignition module=~$140

see my thread on this problem: http://www.ferrarichat.com/forum/mondial/364375-rough-idle-loss-power-backfire.html
Good luck

 

If you have your owners manual book read the part about the operation of the slow down lights. It basically says that at one temperature the light begins to blink at a steady rate. When it achieves a higher level of temperature it goes on solid. If it is flickering or doing something erratic it is not the proper operation of the light. After 4 years of ownership mine still has a mind of it's own. It's become like a pet and I talk to it. Like Soucorp I used to pull over and check the Cat.

The intermittant rough running will take some time, but like said before, check your extenders first. It seems to be a pattern failure that the spark will arc out the side of the unit through the plastic to the valve cover or head. You can really only know by pulling them all and checking them. As a temporary some have wrapped the offending area in electrical tape. Some of my extenders were actually cracked and I wrapped them but never actually had this drivability issue. I don't know what your budget is but I do have all my old extenders, most are visually perfect so if you are looking for a few to play with I have a buddy who lives in Sac who will be coming through Oregon and could bring them down to Sac where you could pick them up. He won't be back down there until near the end of June though and I'm not sure they are that expensive.

Spark plug lead connections from the cap are also special and not something I'd consider bulletproof.

If you have small budget start the extenders, if you have larger budget start with Salerno

Double check my comments on the Slow Down light. I have a 3.2 and that is how it operations, we have only a single light.

 

The spark plug extender nightmares!!! I forgot all about them! I got rid of the old cables and extenders years ago while trouble shooting not passing emissions.

I followed Birdman's spark plug wire thread using Accel 4040 cables. I took the extra step of plugging the wires directly to the spark plugs with long needle nose pliers.

The Accel 4040 has similar Ohms per foot as the original Ferrari ones. I believe both are about 400 Ohm per foot.