Re: Why different spark plugs- 99 Taurus?
"Big Al" <firstname.lastname@example.org> wrote:
> "trainfan1" <email@example.com> wrote in message
>> Awelch wrote:
>> > The owners manual for my 99 Taurus <engine code u> says cylinders
>> > 1,2,3 use plugs with suffix "PG"
>> Platinum Ground electrode
>> but cylinders 4,5,6 have plugs suffix "P".
>> Platinum center electrode
>> > CAN ANYONE EXPLAIN?
>> Different potential biasing in the high tension spark circuits - one
>> ground to center, the other center to ground.
>> The guide for Autolite plugs says Double platinum
>> > plugs APP&^$ are used in this engine. Will I be OK with those?
>> Perfect. Stick with Autolites and you will be "blessed".
>> My question though - do you really have enough miles to need a plug
Sounds right if he's a long distance commuter
> One bank has normal spark polarity, the other bank is reversed. Rob
> hit it right:)
To further illuminate:
Count the coil packs, note you have 1 per each 2 cyls... unlike the
legacy ign systems where one side of secondary (Hi-V) connected directly
to ground, each coil fires once per rev and is wired:
Gnd --plug A -- coil neg &&& coil pos -- Plug B -- Gnd
Thus both plugs are fired on each trigger
Yeh, I'm a Krusty old Geezer, putting up with my 'smartass' is the price
you pay..DEAL with it!