backfiring w new pointless distributor

[jlorini]

I recently had old distributor replaced with electronic pointless distributor on my R-1. Plugs and wires were also replaced. Engine runs beautifully EXCEPT I get backfiring (popping sound) between 2,500-3,000 rpms on decelleration/coasting from that rpm range. This was NOT present with old distributor. Any thoughts on what is wrong?

[new2avantis]

coming off of hard acceleration, or daily driving? what type of dist? whats the timing set to? can be lots of different things. was the system built for a studebaker, or retrofit from spare parts? plugs the right kind/size gap? no wires crossed?

Edited February 28, 2010 by new2avantis

[GAWen]

Personally I love that popping sound, tells me that I have really tuned my car for max performance. But, it is a real indication of a over rich fuel/air mixture at that RPM range.

George, RQB 1600

[ernier]

As an experiment try disconnecting the vacuum advance and plugging the line. If it improves you may have a sticking breaker plate. The vacuum advance is pulling hard at that rpm range while cruising and when you let off the gas the plate should return as vacuum diminishes. Just a thought and easy to try.

ErnieR

I recently had old distributor replaced with electronic pointless distributor on my R-1. Plugs and wires were also replaced. Engine runs beautifully EXCEPT I get backfiring (popping sound) between 2,500-3,000 rpms on decelleration/coasting from that rpm range. This was NOT present with old distributor. Any thoughts on what is wrong?

[ernier]

I just thought of something else...if you have a choice of ported and non-ported vacuum connection on your carb for the advance are you connected to the ported side ( passenger ) side of carb? If you have the original carb ignore this post

ErnieR