Zoltan Finks wrote:
So am I to understand that throttle position has an effect on the metering
of the IP * even before the engine starts (as in while initially cranking
starter)?* It would seem so - otherwise, what could be the benefit of
flooring the pedal while cranking?
Also, what is the reason behind the owner's manual instructing us to pump
the pedal to the floor three times prior to engaging the starter (for cold
conditions)? (BTW, yes, I think it says to hold it to the floor after the
three pumps) This sounds like the pumping of the pedal in a gasser - the
function of which, of course, is to squirt a bunch of fuel down the intake
to get things going.
The greatest effect of pumping the pedal is to insure that the rack will
move freely. Much of the linkage within the injection pump (that
integrates pedal position, engine rpm, engine load, boost or atmospheric
pressure, etc.) involves springs and weights - NOT rigid linkage.
Pumping the pedal moves some parts from one extreme to the other thru
the engine oil and fuel that may be stiff and not permit free movement
without being "shaken up."
If you really want to know what's happening, Bosch has books describing
their operation. The mechanical injection pump is a complex, remarkable
device, made with great precision and capable of precise fuel metering
for 10s of thousands of hours. Few technicians actually understand their
fine points (I sure don't) and it requires very elaborate/expensive
tools to adjust them properly.
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
