96 S320 CODES 36, 84
 

We have a 1996 Mercedes S320 that has code 36 oxygen sensor contorl sys lean stop/mix too rich, and code 84 short term self adaption idle\p load exceeded. Our scanner won't read more that this. The car idles a little rough at stops, feels like it may stall out and hesitates on acceleration. When the car came in, the air box clips were all undone. Does anyone have an idea what could be causing this?

See if there is any evidence of petro in fuel rail Regulator vac line.
If YES, then the Regulator is leaking unmetered fuel into the engine intake.
Common fail part....

http://catalog.peachparts.com/ShopByVehicle.epc?q=1996-Mercedes--benz-S3--0--Swb-Fuel--Injection&yearid=1996%40%401996&makeid=63%40%40MERCEDES%2DBENZ%40%4063&modelid=6430%3AMBC%7C1514%3AE D%7C214%3ASM%7C853%40%40S320+SWB&catid=240621%40%40Fuel+Injection&subcatid=240645@@Fuel+Pressure+Reg ulator&mode=PA

No, there is no sign of fuel. The engine starts to surge at idle after heating up, you get a rotten egg smell from the exhaust, and the readings on the mass air flow goes up to 15, down to 4.44, and back up again.
cold readings (doesn't surge)
intake air flow 9.99, coolant temp 28 c, intake air temp 10, intake MAP 37, ign timing 8.0, fuel sys open loop, absol. throt pos 3.9%, lt fuel trim 0.8%. Would really appreciate any advice. Thank you.

Also, do you know what normal readings are for the mass air flow sensor? Thank you

<<fuel sys open loop, >>


I would check the 02 sen sig under passenger rug for a signal.

We replaced the mass air flow sensor and readapted values. So far so good. Rotten egg smell is gone and car is running beautifully. Thanks for your help.