Here I go again, ranting... I work on cars and
light trucks for a living. I realized yesterday as
I was removing yet ANOTHER set of Bosch Platinum sparkplugs from a
customer's car that
good people on this list mght have fallen into this trap.
In my part of the world the DIY auto parts
stores push these pieces of junk. They are completely unacceptable for
most U.S. cars
and just about ANY older vehicle I can think of.
If you have a BMW, Volvo, Mercedes-Benz, maybe...
Here's what's wrong. I call it "running out of
spark". On the 'scope, a good sparkplug requires 7 to 13kV to fire.
Most systems will
max out (12v electronic ignition) at around 30 to
35 kV. Older 6v systems will be less, 20kV?
The difference between firing voltage and maximum output is like a
reserve. As soon as you put the pedal to the metal that reserve begins
to narrow. Add a heavy GVW, lean mixture, too wide of plug gap, etc, and
the reserve is JUST enough to prevent misfire.
Let's add Bosch Platinum plugs to the mix!
They require somewhere around 80% of max output AT IDLE! You can see
that your ignition
system will "run out of spark" very quickly.
God forbid you forgot to take the choke off or
you happen to be running old gasoline! The
spark will completely bypass this "huge resistor"
of platinum electrodes and just run down the coated insulator.
There MUST be someone on this list who has
had problems with "high performance-long life"
platinum plugs.
I'm not just picking on Bosch, "Split fires", and
other platinum plugs are just as bad.
I know that certain vehicles REQUIRE platinum plugs. Use what came in
them originally.
If I hurt someone's feeling with this, too bad!
It's the truth!
Don Kenyon ASE Certified Master Automotive Technician, L-1, CA Enhanced
Smog License
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