4K Want Bang Now Wont Idle By It Self

[Ryanlovesake70]

So ive rebulit most of my 4k i put it all back together i litteraly just finished opening the new thermostat the day before it ran an idled sweet, i started it the next day then it was running sweet it warmed up i was changing the revs (at about 950rpms idle) till i was happy an then obviously gave it a little squirt then bang now it doesnt wanna idle it self like it still kicks over but it wont start unles i give it gas ?

[ke70dave]

Possibly a bit of dirt stuck in the idle jet.

[B.L.Z.BUB]

Vacuum leak.

[altezzaclub]

Does sound like you've lost the idle circuit... Unless the bang was literally a backfire in which case it might have blown out the inlet gasket.

[rebuilder86]

the bang (backfire) could also simply have jammed the PCV valve open, this causes a large vacuum leak which makes the idle circuit in the carb inoperative.

try simply plugging the pcv valve tube for now and see it it idles.