Start Up Backfire with 32/36 DFEV

[tartan18]

I'm stumped. Got my new 32/36 DFEV carb all set up according to the recommended steps, re-checked my timing (Computronix electronic ignition system) and I have a backfire when I start the engine. Once the engine catches it runs smooth. Very good power going accelerating up hills with no ping, and it decelerates without issue. But if I turn the engine off and re-start it has a hiccup backfire before starting. I have a 1977 with the 1800 engine. Ideas of what to check/adjust?

[RoyBatty]

"Back fire" is a generic term that is sometimes used wrong.
Is the engine firing out the exhaust? Late timing/rich mixture
Or back up thru the intake manifold and carb? Lean mixture/early timing?
Valves can also contribute, but you say it runs fine once it's going so I'm not gonna guess that to be your problem.

[tartan18]

What I call a back fire seems to be coming from the air intake and not the exhaust.

[RoyBatty]

Check your initial timing, it may be too far advanced.
Also check your choke setting. If it's not closing to enrichen the mixture, you could be too lean at the start up.
And it could of course be a little of both.
Do you have the dual point distributor?

[So Cal Mark]

that is a waste spark system, so if you have unburnt fuel in the manifold, it can "pop" when cranking. The correct method for cold starting is to depress the throttle one time to set the choke, then crank the engine with the throttle closed. Make sure the idle speed isn't set too high. If you have run-on when shutting the engine off you'll leave some unburnt fuel in the manifold

[RoyBatty]

Oops, forgot that he had the computronix ignition system.

[124JOE]

Check your initial timing, it may be too far advanced.

Do you have the dual point distributor?

yes i agree if it was timed by ear it may be off quite a bit
or it may have jumped a tooth

[tartan18]

Timing was set with a light and in conformance with the instructions that came with the Computronix ignition system. It is currently set at 13 BTDC. There is no run-on when shutting the engine off. I did note that the idle mixture screw is about a half turn from bottom (nearly full lean) so I will slowly increase this and also back off a bit on the advance. Today it started (after being warmed up) with a slight improvement (only one "pop" out of the air cleaner). I guess this is just going to take a few micro adjustments to get the carb dialed in just right. Thanks for the ideas.