76 3.0 backfires on decel - a litle help?
 

From this thread:

http://forums.pelicanparts.com/porsche-911-technical-forum/625703-how-does-3-0-76-carrara-cuts-fuel-push-mode.html

I believe this is the situation - the car is 76 with a 3.0. When the driver lifts off the gas and begins to decellerate (engine braking) it backfires. I think it's a CIS car and we need to know if there is some kind of fuel cutoff switch like the MFI cars?

According to his first post...3.0 76 Carrera with Bosch K-jet tronic--Guys..let's try to help this guy help his friend...English his his second language so ...GO EASY ! Perhaps this is what is broken..found on PP

The decel valve (or vacuum limiter) prevents the engine vacuum from dropping off very quickly. This prevents rapid changes in the engine timing when letting off the gas, and prevents engine backfiring. 911-110-220-00-OEM Decel Valve (or vacuum limiter) 911 (1978-83) Brand: Genuine Porsche