replaced my Air Mass Meter this afternoon.. Straight forward.. Car will not run. Starts and will idle a second to 10 seconds, then die. Once I get the first start to idle for 5 - 10 seconds before the stall, subsequent starts stall immediately. IDEAS?

While I had the air mass meter off, took a moment to clean the intake throttle and throat with w little MAF/Carb cleaner.

Only one plug connection.. seemed easy. dead car now.. Any suggestions will be appreciated...

Car - 92 400E M119 230Kmiles

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Jeff
'87 300E
'92 400E
'06 ML350

I don't know if this will help, but you replaced the sensor and it costs nothing to try resetting the ECU memory. Below is a post by Arthur Dalton from a few years ago. I sure miss seeing his posts on this forum.
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You can reset adaptation back to Mean Base Line by re-setting/re-activating the ECU memory . After you have cleared all existing codes [Single flash verification ], you then hold button for 6-8 secs. after the single flash. [wait 2 secs after single flash].. Turn off key for 2 secs, On for 10 and then start.

This is NOT a code clear, it is ECU memory reset. That gets your ECU back to Normal . From there the unit will adapt to the new parts and sensors, but rather then coming back from high adaptation extremes, it will come up/down, +/- as required from a Normal Base value.

The ECU can/will readapt from the old memory by itself with drive cycles [ relearn process] , but if the trims were way out , you can still get codes coming back while the process takes place..so, it is easier to just clear/reset the memory after you have changed parts and have cleared the diagnostic codes ..you are then assured of starting with an ECU that has a Mean Base Line setting value..[ ie..a Normal setting]..which should be closer to proper adaptations with the new remedy parts.
Just a short-cut........

Also, as SB mentions..FP regulator leaking diapragm will supply the engine with unmetered raw gas..not only will the engine suck raw, un-metered gas into the intake from engine vac , but the Fuel Pressure will go higher than spec and compound that problem...that would be a first check..
the same can be a vac leak..a vac leak of unmetered air is read by 02 as a lean condition , so th ECU tries to enrichen this false reading, resulting in wrong A/F mix..

Both reg and vac leaks will force trim levels +/- that it may not be able to handle [ beyond limit].........and result in crap MPG/Running condition.
If one does find a leaking/bad FP reg, it is also a good idea to change the oil.

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1993 400E, 256,000 miles (totaled)
1994 E420, 200,000+ miles
1995 E420, 201,000 miles

Replaced with orginal and the car fired up immediately. maybe a bad reman'ed meter...returning part to try another...

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Jeff
'87 300E
'92 400E
'06 ML350

For future reference, where did you buy the reman from?

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1993 400E, 256,000 miles (totaled)
1994 E420, 200,000+ miles
1995 E420, 201,000 miles

Is the hotwire inside the new air mass all in tack. The hotwire must be in tack with no dust or particles on it. The hotwire is really sensitive.

If you cleaned the throttle body with cleaner such as that, it maybe that inhibiting it starting.

I did the same thing two weeks ago - cleaned the throttle body with contact cleaner.

Wouldn't start.

Solution - Full throttle and crank for 20 seconds. It eventually coughed to life.

Update - Returned suspect MAF sensor and got another one. Installed and the car runs GREAT.... it can breath again !.... stumble and hesitation gone. response much improved. Now that I compare this MAF sensor to the first one I picked up, it looks like the first one was either a returned core or a bad part restocked. The working sensor was in a sealed box and the wax paper wrap around the part was fresh and unwrinkled. The former part's box and wrapper was not so new looking.

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Jeff
'87 300E
'92 400E
'06 ML350

The best way to purchase MAF sensor is to cross-check OE numbers found on the old unit (under the hood look at the MAF's housing and read engraved numbers) and compare with the numbers presented with the MAF's description. Sometimes the problem may not be necessarily directly related to the malfunctioning MAF, just get your car scanned by the OBDII tool which is available at most garages. There are plenty of sources where you could buy MAF sensors online. Before purchasing make sure you are getting the correct part.
Note: A mass airflow sensor is used to find out the mass of air entering a fuel-injected engine. The air mass information is necessary for the engine control unit (ECU) to balance and deliver the correct fuel mass to the engine. The sensing element in MAF sensors can be easily contaminated causing hard starting, rough idle, hesitation and stalling problems.
No software re-program of the vehicle's computer is required for the MAF sensor replacement. Easy do-it-yourself installation task.

I hope this information will be useful for you and you'll resolve the problem with your car.

except that this is a pre-obd 92

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former: 83 300D, 97 C230, 93 400E

current: 08 C300 Luxury , 92 500SL