Kevin wrote:
Is a 78 300D's hand pump supposed to lock shut? I've noticed that the
car has been getting hard to start for no good reason (it's not THAT cold,
and the glow plugs seem to be functioning correctly). It is due for
a valve adjustment in a few thousand, but even still...
The pump doesn't leak any, but if I pump it, I can feel the bleedback hose
from #1 to the fuel filter vibrating. Pushing the pump down and turning
either direction does not seem to latch it.
There are at least two different pumps, pumps that lock down the piston
and pumps that don't lock the piston. The vibration you feel is fuel
that has passed through the relief valve and into the return hose, so
the pump is working! That doesn't mean that air isn't entering the pump
or somewhere else in the fuel path and that allows fuel to drain back
into the tank when the car sits for a while. That will require
additional cranking to move fuel into the injection pump before the
engine will start. If pumping the hand pump results in prompt starting
under conditions when the engine is likely to be slow to start, then air
entering the system (often thru the hand pump, but possibly thru leaks
in any of the flex lines) is PROBABLY the cause.
It could be tight valves. I think I'd adjust the valves anyway since
they need it but as the weather warms, even moderately tight valves
won't inhibit starting any more.
Marshall
--
Marshall Booth (who doesn't respond to unsigned questions)
"der Dieseling Doktor" [EMAIL PROTECTED]
'87 300TD 182Kmi, '84 190D 2.2 229Kmi, '85 190D 2.0 161Kmi, '87 190D 2.5
turbo 237kmi
