I have an '84 190E that my father bought new and stored in the garage for 10 years. Total mileage=80k now, after I have had it for close to two years. My dad claims this problem has occured since new. It was the first 5spd in Oregon and when I depress the clutch and as though i were to put it in neutral, the engine drops to around 300 rpms, shudders bad, then comes back up. This happens virtually all the time, especially when driven harder or kept in gear until the car has slowed to around 1500 rpms. I have replaced the fuel pump relay as it went out, alternator, plugs, cap, belts, and also many tune ups. BTW, the problem is less occurant when the car is topped off to the brim with oil. No mb mechanic or dealer has found a fix yet and I'm tired of dropping money into it. I have seen a few rare people online who have the same problem, but no fix. Any ideas?

This problem may be very hard to solve because it sounds as if the engine is having a hard time with the transition from throttle to idle. What if you just blip the shifter into neutral and let off of the gas?

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Benzmac:
ASE CERTIFIED MASTER AUTO TECHNICIAN
LEAD TECHNICIAN FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM

Clarification, the idle only drops after being downshifted or while the vehicle is driving and then the clutch is depressed. If I am driving and I depress the clutch then give it a little gas before the idle drops...it won't drop back down. To answer your question, yes it would almost die and then come back. Thanks for the response!

OK, MB DOC called me and said that there is a service bulletin that says the control module was updated to stop de-acceleration fuel shut off at a higer level (1200 instead of 900) and this will solve the problem!!

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Benzmac:
ASE CERTIFIED MASTER AUTO TECHNICIAN
LEAD TECHNICIAN FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM