II checked my EHA duty cycle, i get
30.2% key on, engine off
50.3% at idle
anywhere from 30-49% with throttle open
could i have a bad mass air pot?

__________________
1984 380SL-driving and service privileges.

if it is fixed at 50% during idle operation you may want to consider an O2 sensor.

The O2 was replaced in 2000, could it be bad now?

__________________
1984 380SL-driving and service privileges.

Disconnect the O2 and give us the readings then.

will do this weekend.

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1984 380SL-driving and service privileges.

nthach

Are you sure you're getting 30% key-on, I think it's 70% on Federal cars and Euros (like mine).

Did you use a regular digital multimeter with the formulae or did you use one with a duty-cycle function?

Fixed 50% idle when warm indicates O2 sensor inactive.

If the duty cycle remains fixed at 50% when the car is warm, check the O2 sensor.

The duty cycle should fluctuate once the car is warm if the O2 sensor is working.

Cheers.

Yea, i got 30% key on/engine off(deadhead). I used a Sears multimeter with the duty cycle function.

__________________
1984 380SL-driving and service privileges.