M103 Air Flow Sensor Plate

[d2bernhard]

Hello,
‘86 300E W124 M103 226k miles
Yesterday my car would not start. I determined OVP Relay. Replaced and the cranking did sound encouraging but still no start. Frustrated and guessing I should take a look for a lose something, I lifted the air filter housing and found the Air Flow Sensor Plate (the thing the air filter feeds into) was stuck up. I pushed gently and freed it and it started right up. This happened to me once before years ago. Both times there was a LOT of cranking and start and die and restart etc. involved. There is a job in the MB book to align this thing. Should I bother?

[d2bernhard]

No one?

[sbourg]

If you carefully clean the sensor plate rim and the meter body bore, you may remove deposits that caused the sticking. If it then still does not move freely and without catching, it still seems unlikely realigning the plate would correct the source of the problem, which is likely an internal worn part. If cleaning did not solve the problem, I would remove the airflow meter, disconnecting all the plumbing, and remove the rubber lower plenum for inspection and possibly more complete cleaning - before attempting ANY adjustments. Then, if an adjustment would save replacing the airflow meter, I would cautiously attempt it.

Steve

[300holst]

Why was the plate sticking? Was it out of position or are there sticky deposits on the throat of the intake where the plate moves? You might try some carburetor cleaner first on that area.

[saumil]

The problem could actually be in the fuel distributor, its shaft may be sticking. There is not much else to cause hard sticking of the plate.

[brewtoo]

I agree with Mr. Patel.

[david s poole]

unless someone loosened the round plate and did not centre it properly before tightening up the bolt.clean thoroughly first and then grab the bolt head with a pair of pliers and pull upwards.it shouldn't stick should drop right back down to original place when you let go.