trader4@[EMAIL PROTECTED]
wrote:
> On Jul 13, 1:54 am, RF <R...@[EMAIL PROTECTED]
> wrote:
>> RF wrote:
>>> -->> T.G. Lambach <<-- wrote:
>>>> I can't help you on the vacuum system's details but the theory is
that
>>>> a leak somewhere allows air to be pumped into the motor (via the
pump)
>>>> and that excess air blows lube oil into the air filter. A Mity-Vac
(or
>>>> similar name) vacuum pump can be used to find vacuum leaks.
>>>> I (eventually) found that my 617.950 engine blows oil up the air
>>>> cleaner's oil drain pipe on hard acceleration, staining the paper air
>>>> filter, whenever the oil level was too high due to careless repair
>>>> shop overfilling on an oil change.
>>> A belated thanks TGL for the info. I have been bogged down with other
>>> things recently and will be looking at this problem again soon.
>>> This is the first time I have seen lots of discrete oil drops. The
>>> filter normally has a
>>> uniformly sprayed look in places and moderately clean at others.
>> I finally got around to this problem in which my
>> '83 240D's air filter is becoming very spattered.
>>
>> The oil level in the engine is about 1/4" down
>> from the max level. As T G Lambach (thank you TGL)
>> suggested, I have acquired a vacuum pump and now I
>> have to figure how to apply it. I lifted the cover
>> of the air filter and there were several large
>> drops of oil at the mouth of the incoming pipe
>> from the cylinder head cover and the filter was
>> more spattered than a week ago.
>>
>> Most fortunately I chose a car with the least
>> possible complications and, as a result, I have a
>> very simple vacuum system. There is a single white
>> line about 3/8" diameter going from the vacuum
>> pump to brake unit. About a foot short of the
>> brake unit there is a T junction off the 3/8" line
>> which then splits into two small pipes - one light
>> brown and one dark brown. Both of those go through
>> the firewall, possibly to the steering lock.
>> Another light brown pipe, of the same size as that
>> small pair, comes back out of the firewall and
>> connects to the valve (a check valve?) on top of
>> the injection pump. I don't yet know how the three
>> are connected in the dash area. My 3 big fat
>> manuals seem to have no diagram of this vac
>> system. They do have several for the later EGR
>> system. I believe there are line diagrams in the
>> manuals for the vacuum but I couldn't find it.
>> Looking for something in those manuals is like
>> going down a great black hole.
>>
>> I propose to pull the two small pipes off the T,
>> plug the hole with a golf tee, and then measure
>> the pump pressure.
>>
>> Then I guess I could apply the pump to the two
>> light+dark tubes and see if the car key position
>> makes a difference.
>>
>> Finally, and this one has me stumped, the
>> connection to the injection pump. Is the function
>> of this to lower the pressure in the pump so that
>> the suction speeds the fuel into the pump, and to
>> provide a check valve to keep the fuel from
>> getting onto the vacuum lines?
>>
>> TIA- Hide quoted text -
>>
>> - Show quoted text -
>
>
> The vac line to the injection pump activates a bellows that shuts of
> the fuel flow and hence stops the engine. It's activated from a vac
> valve on the ignition switch. If that line develops leaks, the car
> will start to take longer to stop when the key is turned off. If it
> leaks real bad, the car will not stop at all.
>
> I'd check where the vac lines go through the firewall. On my 300SD I
> had two fail right at that point. Not sure why, it wasn't a sharp
> bend or anything. Could be vibration perhaps. When trying to find
> the leak, I just wiggled them a bit and the bad one broke right off.
>
Thank you Trader4 for the info.
I traced the lines I mentioned in the last post
and found that the dark brown tube is redundant
and plugged. One of the light brown lines goes
from the T on the 3/8" line to the steering lock
and then back to the injection pump - the return
leg has a faint bluish stripe in it. The tubes
pass through a rubber grommet in the firewall and
they are well protected there. They look almost
like new.
Yesterday I tried to start the car, after a week
of being idle, and it was slow to start, so I bled
a litttle more air from the fuel line. In the
previous week I replaced a gasket between the
injection pump and the engine block, so I had to
take out the pump and all the fuel lines around
it. Yesterday after it started I drove around the
block. Finally I turned off the ignition and the
engine stopped immediately, so I guess the vac
line to the pump is working ok. It seems to me
that this doesn't solve the problem of the
spatters on the air filter.
Tomorrow I will start the engine and check the
vacuum level in the 3/8" line with it attached to
the brake unit and with it disconnected. I don't
like the noise the engine makes in this quiet
neighborhood and tomorrow, Monday, is a better day.
Have a great week :-)
|
