popping on deceleration

[ah53]

Just got my '71 280sl back on the road after having it apart for 3 years.  I have always had a problem with "backfiring" and popping on deceration. I have read the posts on the topic and am wondering if a consenus has been found on how to fix the problem.  I looking at the vaccum governor as the culprit but would appreciate any input or thoughts.  Thanks

Joe

[Cees Klumper]

If I were you I would check the proper operation of all of the components of the ignition, including the vacuum governor (check the timing at the different listed RPM's with and without vacuum attached). But I think that where you set the timing in absolute terms also has a lot to do with this. Finally, I recall reading that a leak at the exhaust manifold somewhere can also cause popping (now is popping the same as backfiring?).

Cees ("Case") Klumper in Amsterdam
'69 white 280 SL automatic

[ah53]

Cees

   To me popping and backfiring are somewhat similar, just that backfiring seems to make people on the street duck.  I just changed a cracked exhaust manifold and replaced all gaskets with new ones in the process.  Also all the "knuckles" of the accelerator linkage were replaced and the linkage set according to the manuel.  With the exception of this problem the car is running the best it ever has in the 15 yrs. I have owned it.  I have never checked the timing and I guess it's now time to do so.  Thanks.

Joe

[jeffc280sl]

Do you have an auto or manual trans.  Both have emission system switches that shut off fuel, etc? under certain conditions.  Look in the Haynes manual for info.

Jeff C.
1970 280SL 4-speed

[n/a]

Hi Joe,
I had a problem with some backfiring on deceleration several years ago.  It turned out to be bad ignition points.  Replacement and proper gapping cured it.
Just a thought.
Best regards,
Don