engine stumble on deceleration

[96witton]

Hi, my 1969 280sl runs great. the only issue I seem to have is when I am decelerating (lower speeds, under braking) the engine stumble's. I have new injectors and have preformed a linkage setup check. I am thinking of going with an electronic ignition system? any suggestions? p.s. the car pulls very well and idel's great.
thanks Jim
 

[roymil]

If you have a stick, are you in 3rd or 4th gear when you let off the gas?  clutch in or out?    a  US '69 will have some smog devices that might be initiating, or maybe not.   Either case may cause some different noises and behavior so pay attention to which gear and clutch state when you hear things.   It might be the injection pump shutting off during decell, and it could be not shutting off and sending a bit of raw fuel to exhaust and making noise there.   the BBB has details under the pollution control addendum.  Neither is a problem though.

[rwmastel]

Hi, my 1969 280sl runs great. the only issue I seem to have is when I am decelerating (lower speeds, under braking) the engine stumble's.

When stopped, in park or neutral, do the RPMs rise when applying the brakes?