Jim Cathey wrote:
need to put a light on the GPs and see how many seconds they're
staying on
when cold. We're getting mid 30'sF in the morning so I should get a
lengthy
glow.
Around freezing you should be seeing something like 30 seconds
of glow. If you don't, just wait that long anyway before starting.
It ought to start a lot better. (You don't need a functioning light
to get a good start, if you know how long you're supposed to wait.)
Until temps get well below freezing, between 5-10 seconds is as long as
the dash lamp should remain illuminated (if the relay is properly
working). By zero deg.(F) that might extend out to 15-20 sec (although
the later plugs optimized for afterglow heat MUCH faster and take only
10-15 sec to reach 1180 deg C vs 30 seconds for the older style plugs).
It is usually desirable to allow the plugs to heat for an additional
10-15 sec AFTER the dash light extinguishes before once temps drop below
freezing.
The time constant that controls the duration of the dash lamp and time
until power is turned off consists of a temperature sensitive resistor
and a capacitor. When stored without being periodically energized, the
capacitors deteriorate and after as little as a year they may fail and
the temperature defined delay drops to almost nothing. Sometimes they
can be revived by cycling them many times - and sometimes that doesn't
work.
Marshall
--
Marshall Booth Ph.D.
Ass't Prof. (ret.)
Univ of Pittsburgh School of Medicine
[EMAIL PROTECTED]
