Peter Arnold wrote:
Dave mentioned that changing the "Delivery Seals" may repair my pump.
Is that in the POS manual? Parts & Tool from my usual Source {Rusty
or Salvation Army Thrift Shop}
I will be trying to advance the idle screw clockwise tonight per
Marshal's suggestion.
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Delivery valve seals will NOT fix a problem with idle speed adjustment!!!!
Replacing delivery valve seals is RARELY needed, but IF required,
nothing else will solve the problem. Maybe 1-2% of Mercedes injection
pumps require them during their lifetime. There is really NO reliable
test of delivery valve seals except with the pump on a test stand. It is
probably wise to replace the pump seals IF you're going to replace the
"O" rings on the delivery valve pipe fittings as the seals are
inexpensive, but it's rarely actually necessary. The only reason to
replace the seals is if there is uneven delivery from the IP to the
injectors. My very crude test of delivery seals is to remove all the
injection lines and crank the engine while watching what comes out of
the pipe fittings - each should deliver about the same amount of fuel. A
really proper test (the way it would be done on a test stand) would
measure the output and pressure of each port during some number of
revolutions of the pump - each should deliver about the same amount of fuel.
When playing with the injection pump a little finesse and care is
required. The pump body is quite easy to distort if anything is
overtightened (usually "repaired" by loosening and retightening using
the proper torque/release technique as outlined in the Tech Data
Manual), or a little too much force on a wrench CAN crack the housing
and if that happens a new pump is the only solution.
I do NOT recommend people trying to "tune up" their injection pump as
injection pumps rarely fail, do NOT routinely drift out of adjustment
and about 90-95% of all injection pump problems occur right AFTER the
pump has been "adjusted." Only if all of the injectors have been TESTED
and shown to be working PERFECTLY but fuel delivery still seems uneven
is there sufficient justification to even consider playing with the
delivery valve seals (in MY opinion). Get half a dozen new seals AND "O"
rings (and several spare "O" rings as it's easy to damage one or more
when installing the delivery valve fittings). Oil the "O" ring when
installing it. You'll need the splined socket and a torque wrench
accurate in the 30-40 lb-ft range. The fittings CAN be removed with the
intake manifold in place (but it's a little tight).
Worth checking the engine manual.
http://mb.braingears.com/124_DISC1/Program/Engine/602_603/07.1-8627.pdf
Marshall
--
Marshall Booth (who doesn't respond to unsigned questions)
"der Dieseling Doktor" [EMAIL PROTECTED]
'87 300TD 181Kmi,'87 190D 2.5 199Kmi, '84 190D 2.2 227Kmi, '85 190D 2.0
159Kmi, '87 190D 2.5 turbo 234kmi
Diesel Technical Advisor MBCA, member GWSection
http://www.dhc.net/~pmhack/mercedes/mbooth1.htm
