Vacuum problem w123

[Chris B]

Hi All
I am new to this group but I really hope to get answers. I drive a 1986 w123 230e
.
It just died the other day with no apparent reason, had to tow it home. Now it starts but have to keep the foot on the gas to keep it alive. I notice that the vacuum econo gauge is not behaving as normal. Do I have a vacuum leak? And how do I start to find it? Any help would be great , thanks

[Roland Franzius]

Post by Chris B
Hi All
I am new to this group but I really hope to get answers. I drive a 1986 w123 230e
.
It just died the other day with no apparent reason, had to tow it home. Now it starts but have to keep the foot on the gas to keep it alive. I notice that the vacuum econo gauge is not behaving as normal. Do I have a vacuum leak? And how do I start to find it? Any help would be great , thanks

A common problem for an old 123 injection engine.

The most common problems are

no vacuum in the engine house because of leaking crankschaft gasket
or oil debris in the hoses between camshaft hood and intake manifold

defect vacuum membrane or heating element in gas enhancement membrane in
cold start regulator

defect membrane in idle air bypass regulator

defect fuel pressure regulator.

For design look at

http://www.auto-parts.spb.ru/cat/cats/m.mycat?cat=mb

Select car -> Engine M102 ->09 Air Cleaner -> 060 Idle Air System
and car -> Engine M102 ->07 Injection -> 015 KE-Jetronic and 135
KE-Jetronic Control
car -> Engine M102 ->14 Intake Manifold -> 120 Vacuum System

The front crankshaft seal ring is at

car -> Engine M102 ->01 Engine housing -> 030 Timing Case



Advice: Replace all parts in the fuel system containig elastics,
begining with the hoses at the fuel tank.

The original hoses, membranes and gaskets were not really made for
ethanol and other agressive additives after 1990.

[Chris B]

Hi All I am new to this group but I really hope to get answers. I drive a 1986 w123 230e . It just died the other day with no apparent reason, had to tow it home. Now it starts but have to keep the foot on the gas to keep it alive. I notice that the vacuum econo gauge is not behaving as normal. Do I have a vacuum leak? And how do I start to find it? Any help would be great , thanks

Thanks for that, but new developement. I checked all the vacuum hoses all seem ok. Now the car starts and idles as before but no oil pressure is shown on the gauge and the econo gauge is still hovering in the middle somewhere. What now do I pull the motor?

[t***@optonline.net]

Post by Chris B

Hi All I am new to this group but I really hope to get answers. I drive a 1986 w123 230e . It just died the other day with no apparent reason, had to tow it home. Now it starts but have to keep the foot on the gas to keep it alive. I notice that the vacuum econo gauge is not behaving as normal. Do I have a vacuum leak? And how do I start to find it? Any help would be great , thanks

Thanks for that, but new developement. I checked all the vacuum hoses all seem ok.

As Roland pointed out, there are a lot of sources for a
vacuum leak besides the hoses. And even with the hoses,
in most cases you can't really see all of them.



Now the car starts and idles as before but no oil pressure is shown
on the gauge and the econo gauge is still hovering in the middle
somewhere. What now do I pull the motor?

Are you sure that it was displaying oil pressure before?
No oil pressure even when the engine RPM is increased
above idle speed? It could be related, but sometimes
when one thing goes wrong and you start looking around,
you notice something else that might have been there
for some time and is unrelated. Let's hope that's the
case....

[Roland Franzius]

Post by Chris B

Hi All I am new to this group but I really hope to get answers. I drive a 1986 w123 230e . It just died the other day with no apparent reason, had to tow it home. Now it starts but have to keep the foot on the gas to keep it alive. I notice that the vacuum econo gauge is not behaving as normal. Do I have a vacuum leak? And how do I start to find it? Any help would be great , thanks

Thanks for that, but new developement. I checked all the vacuum hoses all seem ok. Now the car starts and idles as before but no oil pressure is shown on the gauge and the econo gauge is still hovering in the middle somewhere. What now do I pull the motor?

No oil pressure means
- manometer in the odometer unit has a leak (oil inside the dash)

- oil pump has gone

- the oil channels in the motor block or head have a leak

- head gasket leak

- oil cooler leak

If there is no oil pressure the engine game is over. Open the filling
cap during idling to see if there are oil drops flying around.