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What are these two vacuum things for?

732 views 4 replies 4 participants last post by  alibttb 
#1 ·
Hi all.
I have bought a 230te from 84’ with man. trans. It has not been well maintained over the years and I see several places where the PO made some strange fixes that I now need to get right.
Anyway, there is a blocked off vacuum outlet at the botom of the intake manifold pointing forward. Where was that surposed to go?

And secondly there is a small box to the left of the engine compartment that has two vacuum lines connected along with at two pin electric connector. What does it do? There is also a knob on it that can be turned.

Will try to attach two pictures. But if that failes I hope that I have described two things well enough to understand.

Best of regards from Denmark.
 

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#2 ·
#1 looks like a manifold vacuum source, maybe ported for the distributor's vacuum advance .

#2 looks like a relay .

I don't know this engine well but there's a start for you ~

The #1 is easy to discern by attaching an inexpensive vacuum gauge and running the engine ~ if not vacuum until you give it throttle, it's a ported vacuum source for either timing advance or maybe the E.G.R. valve....

Often there's a temperature controlled delay relay in the E.G.R. circuit .

If the E.G.R. valve doesn't hold vacuum you've prolly found what it's all for .
 
#3 ·
Could you please post the engine model number, I have got 230TE M102.980 and I don't have this box-shaped valve.

anyway, the vacuum outlet is a manifold vacuum on the throttle, it's used for vacuum advance and should be connected to the distributor, this is not ported, and in your case, as you have manual transmission this should be used to retire the spark, notice that the distributor has two vacuum connections, one for advance and one for retire, and the throttle assembly has two vacuum outlet one that is ported and this one that you show in picture, the ported one is on the opposite side just under the intake manifold.

as for the box-shaped thing, it should actuate the vacuum controlled fuel cut-off valve (Decel valve) I have round one with the same connections but still trying to figure out when it's energized and why.
 
#5 ·
I think you are right, the manifold vacuum should control the fuel cutoff valve in normal situation, but with ac turned on you don't want to lean the mixture when you take your foot of the throttle via the decel valve which will stall the engine with the compressor engaged, so the ac will energize the solenoid that will disconnect the manifold vacuum from the decel valve.

it makes more sense now. ?
 
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