1988 Mazda B2200 smokes for 10 to 15 secs on start up

1988 Mazda B2200 Cab Plus 2.2l mileage: 135,000. The vehicle smokes just for ten to fifteen seconds after starting then goes away. This happens only when cold. I gave the vehicle a compression test and cylinders 1, 2, and 3 have 160 Psi and 4 has 165 Psi. The plugs are clean and are burning even, no oil on them. Warm starts are fine. One thing that is strange is that the smoke starts a "few seconds" after startup and not right away. Should I worry?