4 then 5 then 6 cylinders when cold

[bryant.cw]

When its very cold out, ie below freezing, my car starts on 4 cylinders and then ramps up to 6 in about 30 seconds. Air leaks? How can I look for them?

I just want it to run as new. Just had the head rebuilt because of leaky valve guides and it runs much better, but still having this issue.

[jlevie]

This could be any of a number of things, but until intake leaks are ruled out there is no point in investigating the other possibilities. Have a smoke test run on the intake.

[surebimmer]

Spray parts wash on the intake and throttle body and see if it runs better. Smoke test would be better, but the parts wash test is a easy DIY.