: Backfire

05-18-04, 03:48 AM
I'm almost there with my 69 Caddy hearse. After installing my new Edelbrock 1411 Carb and adding a new vac. advance on my dist. the car is running with all kinds of pick up and speed. I always knew these 472 motors could haul butt. I was experiencing "bog" when accellerating. My old 69 Q-jet had served the car well for many years but it's time had come. Even after installing the Edelbrock carb it didn't quite have the get up and go. This led me to the vac advance. Installed a new one and WOW! The only problem I've found is if I floor it, you can really hear the four barrel kick in now, the car takes off like a bolt but if I back off the throttle quickly it will decellerate and then all of a sudden "POW" a backfire. Now accellerating up the on ramp to the interstate is great because you don't have to back down on the throttle quickly. Even under normal driving conditions no sign of a back fire. Only when you floor it, reach high speed and then back off the throttle quickly. Could this be a timing issue? Maybe time for some new points and condenser? Gonna ask around. I was thinking about a conversion kit for the dist. but I've been reading some negative things about them on some other sites. The engine seems to be running a lot cooler now. I suspect with that bad carb and vac. advance the motor was working harder than it should. Boy even when you shut the motor down it sounds good. I'm really starting to love these motors. Thanks.:coolgleam