Steve MacSween wrote:
Back to my sick 240d... which I am pleased to say continues to recover by
degrees, but I'm not making any success announcements yet. I drive it for an
hour every day.
The smoking problem is just about finished. In fact, I am increasingly of a
mind that what I had/have here, was two problems.
When I had the car at the shop the owner said he checked pump timing and it
was dead on. He did not road test it, tho.
HOWEVER, when I took the car back for my round of "valiant measures" before
declaring it done, I noticed that it snaps/pings/knocks when you give it
throttle on takeoff. Not constantly, just for a second when you take off
from a stop. (I mentioned this before and several people said it was just
the injector nailing on a dead cylinder... but that cylinder is no longer
dead all the time, only an intermittent 'soft miss' at idle in gear and it's
singing its heart out under load.)
Now two other diesel mechanics have heard this and said the timing has to be
off. Also suggesting this is that the thing is eating fuel, and I mean
eating it. Just FYI, the car now has 302k, chain was done at around 200k.
SO THE QUESTIONS:
1. Is there any timing advance on the pump?
Not on the pump - on the chain driven "timer" that the pump bolts to.
2. If yes to #1, how is it controlled? Is the 'mushroom' on top of the pump
involved?
It is controlled by engine revolutions - centrifugal. No adjustment - it
works or it doesn't.
3. If yes to the mushroom, what happens if it's defective?
Has nothing to do with any "mushrooms."
4. Is it possible for IP timing to test out okay at rest, in a static (drip)
test, but be off under running conditions?
Only if the timer is bad. If it's bad, it needs to be REPLACED.
I believe you're on the wrong track. The noise you are hearing is
combustion noise - that results when the combustion wave isn't smooth.
This can be caused by poor injection pressure (either the delivery valve
seals or the condition of the injectors can be responsible for this),
poor spray pattern, or poor conditions inside the prechamber (debris
inside or the prechamber is cracked).
As far as fuel consumption goes, you're not likely to change more than a
few percent with timing changes that are practical. Factors such as
engine operating temperature or leaks or spray pattern or chamber
condition will change fuel consumption FAR more.
You're trying to apply what you know about gasoline engine to a diesel.
Doesn't work very well!
Marshall
--
Marshall Booth (who doesn't respond to unsigned questions)
"der Dieseling Doktor" [EMAIL PROTECTED]
'87 300TD 182Kmi, '85 190D 2.0 161Kmi, '87 190D 2.5 turbo 237kmi, '84
190D 2.2 229Kmi (retired)
