Stalling problems, Chevy 305

[Stuball]

Hoping you guys can help diagnose a couple of problems with my mates chevy astro van (its an automatic)

Running a holley carb (unsure of size) and electronic distributor

Just recently, if you floor the throttle from a standstill, or whilst only just moving, the engine initially revs, then pops back through the carb and stalls., weve tried adjusting the timing to no effect Its Not done this before so we are a bit perplexed.

If you floor it whilst on the move it accelerates nice and smoothly

Other problem is when pulling up to a junction and braking firmly the engine will stall say 75% of the time, have fitted a thermal carb spacer but again doesnt seem to have made a difference (although the carb stays much cooler now)

Any help much appreciated!!

Stuball

[Eliot]

Check your accel pump - i think a backfire means its too lean (or was it too rich!)
Easy to adjust a click or two either way.
Also check your float levels wrt to stalling on braking.

[Stuball]

Cheers for that elliot.

We shall give it a few tweaks tomorrow and see what happens, ta

Stuball