How to tell if your Mercedes W123 vacuum lock is leaking?

How to tell if your Mercedes W123 vacuum lock is leaking?

Connect your vacuum gauge to the line just disconnected from the first “Y” 3-way connector inside the car. Pump a vacuum of 10 to 15Hg. If this line shows a leak, it means this line is cracked, likely where it passes between the body of the car and the door. If it does not, the line is OK. Make note of the results and continue.

Why does my Mercedes W123 230E die at idle?

The un-throttled rush of air into the cylinders also decreases pumping losses. The electrical switch is to ensure the valve only opens during deceleration/overrun, not at idle. If you connect the air valve directly to high manifold vacuum at idle, the engine should die.

What are the problems with the Mercedes 230CE?

The problem that I have with my 230CE with a manual transmission is that the valve is open at idle and when I apply throttle the engine stumbles as the switch changes state and the air valve closes changing air flow from this circuit to the sensor plate.

Where is the lock line on a Mercedes W123?

Plug the end of the lock line that is inside the door. Retrieve your vacuum pump from under the hood to use it inside your car on the next step. Once inside the car, the lock and unlock vacuum lines travel beneath the carpets and in some places underneath flexible black plastic covers.

The un-throttled rush of air into the cylinders also decreases pumping losses. The electrical switch is to ensure the valve only opens during deceleration/overrun, not at idle. If you connect the air valve directly to high manifold vacuum at idle, the engine should die.

The problem that I have with my 230CE with a manual transmission is that the valve is open at idle and when I apply throttle the engine stumbles as the switch changes state and the air valve closes changing air flow from this circuit to the sensor plate.

Is the Mercedes-Benz W123 230E made with lambda sensors?

No W123’s in SA were manufactured with lambda sensors. What you can check is the Warm Up Regulator (WUR). According to your year model it may be that the fuel is leaking to the vacuum line that ensures acceleration enrichment. No W123’s in SA were manufactured with lambda sensors.