LarryT wrote:
Hi JimC,
Hope you're out there ;-) I've pulled the intake and removed the GPs -
tested them by attaching each in turn to a Batt chgr and all glowed red hot
at the tip within ~12 sec. from the chart in the book that's pretty good -
of course, they're all only about 4 weeks old.
I wrote:<< preglow light goes out within 1 sec. of turning the key)
You replied --> That sounds like a problem internal to the GP relay. >>
Ok, the relay was replaced 4 weeks ago also after it failed to light up the
GPs one night when my wife wanted to come home. A new replay gets the GPs
to light but the light goes out within 1 sec (about 1/5 sec) and it feels
like only 4 GPs are preglowing.
So, does this sound like enough testing to convince MB to replace the relay?
I hate to buy another one (from Rusty this time) but if I have to so I'm
sure it'll start and run properly I will.
I tested the wiring between the relay and each GP - all have .4 ohms
resistamce - don't know what else to test.
What do you think? Should I just button things up?
Glow plug relays that sit on the self (or in a car) for months or years
without power being applied to them often have timing problems. The
capacitors that determine the timing seem to deteriorate and that leads
to very short intervals. You MIGHT get perfectly good starting by
allowing the plugs to glow for 5-10 seconds AFTER the light goes off
before starting, but that's not an ideal solution - that assums that
power to the plugs continues for the proper period after the lamp goes
off and the post start glow function timing is proper.
There was a TSB about cycling a preglow relay that exhibited
foreshortened intervals about 10-12 times in a row (turn on the glow
plugs and allow them to remain on until the relay cut off - and repeat
10-12 times - will likley run the battery down, but MAY revive the relay
and timing MAY return to normal). This TSB (early/mid '80s as I recall)
referred to new and used preglow relays that exhibited short timing
intervals after being stored and not used for montns or years.
Marshall
--
Marshall Booth Ph.D.
Ass't Prof. (ret.)
Univ of Pittsburgh School of Medicine
[EMAIL PROTECTED]
