456MGT Sluggish - Need Help!

Kent:

You are a sensitive driver if you can tell when only one plug is misfiring !

1) The 456 series are now getting old enough that certain problems
with running are starting to appear ( I know - I own three).

2) suggest swapping plugs as the first diagnostic, and see what you find.

3) You might also see if that injector is consistantly "squirting."

4) The 456 series has completly seperate fuel systems for each bank of 6 cylinders.
ie: each bank has it's own tip-over switch, timing sensor, fuel pump, etc.

5) When the fuel pump rubber isolator starts to disintegrate
(and they have gone on all three of mine, and been replaced)
the pumps shut down, and that bank goes "off duty".

6) Pumps are about $500 each (need 2),
but the rubber parts are under $100.

7) If my car starts having that type of running problem, I
replace pumps AND rubber parts, assuming that if there
was enough "crap" in the pump to shut the system down,
the pump was not long for this world.

Do the job at home, not on the road....

8) If you do the rubber parts BEFORE they disintegrate,
you could be in and out of the shop in less than a day,
and maybe under a few hundred dollars....

Good luck !

Scott

 

very good info scott. thx

i recently had a similar experience on my 456mgt daily driver. took it to the dealer to hook it up to the computer - which actually didnt yield anything conclusive. so they swapped out all the plugs, and checked the wires. about half the plugs were fouled to some degree. after the switch that all ran well. so that would the first thing i would try kent.


now scott, while i have your attention maybe you can identify some other ailments my car has.

- for a few weeks now (actually ever since i got it back from the dealer plug swap), on cold start up, i get a whirring noise from the engine area, but also central to the car. it increases in volume and pitch as i turn the wheel and reverse out of my parking spot. after the car warms up about 10+minutes later, this sound goes away. but i think it is getting worse.

- i am scheduled to take it in to my usual mechanic to have the thermostat replaced because the water temp now goes one full notch higher on the dial than it did a month ago. i guess a new thermostat will solve that. do i have to use ferrari oem or is there another thermostat (cheaper) that i can use?

- the light in the oil temp dial is somehow intermittent. it has not worked for years, and i have ignored it since i did not feel like incurring the expense or bother to take apart the dash to change one little bulb. BUT then after the dealer switched out the plugs a month ago, the light briefly worked. it worked for a few nights, and then not anymore. so the bulb is not out. could it be a short? or is it something else? how could it relate to switching the plugs??

 

I would also check the fuel filters and the fuel pump first.
Second I would have a look inside the fuel tank to see what is floating in there....

 

Hi,
...had a similar problem giving hesitations and misfiring. Root cause was a broken spark plug.
regards, Jan