Ghosts in my engine bay, Carburetor "Ghost Chuff" Options

[infraredcalvin]

For all you carb gurus -

I haven't quite nailed down the sequence to make it happen, but I get what seems to be one cylinder slight combustion when I flick the accelerator on my cold engine.

Background info:

When I'm done driving the car I'll shut down the fuel pump prior to shutting down the ignition so the carb bowls drain down a bit (cuts down significantly on fuel smell in garage). I don't run them dry, but they are at least 3/4 empty when I shut off ignition.

The following week I'll come out and "prime" the carbs (from the engine bay). This usually entails flipping the fuel pump on, letting the bowls fill, flicking the linkage to get some fuel down the cylinders.

At this point I sometimes get a little "chuff" and see a bit of smoke coming from one of the cylinders out the carb. Mind you, this is on a motor that has been sitting a week, so everything is completely cold, and the ignition (separately switched) is still off.

Could this be compression combustion? Is this common in carbed high compression engines?

Anyone ever experience this before?

BTW this is a modified 3.4 -6 with aftermarket fuel pump and dual plug wasted spark ignition (both separately switched power), I've been sorting since I bought, more info in here starting at post 60 if anyone interested in my saga:

http://www.914world.com/bbs2/index.php?sho...41343&st=59