[john walker's workshop]

pressure bleed-down would be a hot start problem, not cold. you don't have a "start" problem, because it starts. you have a "too lean, cold running" problem. the warmup regulator can be adjusted to run richer, do a search for adjustable warmup regulator, for the procedure, but first make sure the hot CO is adjusted to around 3-3.5%, and leave the oxy sensor plug disconnected. sometimes it's just a tuning issue.