See if the air bleeds are dirty, clean with lacquer thinner & swab, or shoot a little carb cleaner in them.
Look at the bottom of the bowls on AFB/AVS to see if there's any debris or corrosion, and inside the venturis to see if it's sooty.
Left the AFBs on my Street Hemi untouched for 10 years once they were sorted out; it sat during winter in a heated shop with Sta-Bil added to the bowls. Lit off every Spring/Summer without a problem. Same with the racecar's Holley DP.