Can it be explained why, when my choke is hooked up, that when on cold start, the engine revs up and down in a consistant manner until warm? Almost like you are sitting there and doing it yourself to warm up. Of course you disconnect the choke and it will not do that but does fast idle until warm.

1972 3.5 in a SLC
116.982 engine code

Other than this is run wonderfully and very strong. 86,000 original miles.

Thank you,
Tim