Jim Cathey wrote:
In a sense. If they're drawing proper current (55A) at all
they're not dead. The plugs themselves are very robust, and
I believe will outlast the parallel plugs by a considerable
degree. The connections to them, however, are vulnerable to
corrosion. Each plug should measure approximately 1V between
its ring and tip terminals while glowing. I've had trouble
with bad connections on my 240D skewing this so that one or
more plugs isn't getting full heat.
In my experience (5 cars with loop plugs) loop plugs usually require
service at least every 75-100kmi. It MAY not only be the plugs that are
the problem, but the carbon deposits around them (always ream out any
carbon deposits whenever loop plugs are removed) and poor connections.
The loops really are NOT ideally positioned - I don't think they project
far enough into the prechamber - the parallel plugs put the heat in a
much better place. Then there is the matter of more then half the heat
being OUTSIDE the combustion chamber. The connections all MUST be pristine.
Every person that I've suggested parallel replacements to (and followed
my advice) has thanked me and said it made a HUGE difference when
starting the engine cold.
A battery with a high resistance internal connection COULD be the
problem. Not real common with a quality battery that's only 2 years old,
but it DOES happen. Have the battery load tested.
Marshall
--
Marshall Booth (who doesn't respond to unsigned questions)
"der Dieseling Doktor" [EMAIL PROTECTED]
'87 300TD 182Kmi, '85 190D 2.0 161Kmi, '87 190D 2.5 turbo 237kmi, '84
190D 2.2 229Kmi (retired)