[ihdieselnut]

hey guys my dually has started a bad morning trend, it starts easily but when it fires it smokes a lot of blue smoke for 1-2 minutes and skips until it starts to warm up. what could it be ??????????????injector o-rings? a sticking/leaking injector? i just did all the glow plugs, under cover wiring harnesses, and valve covers back in jan. once the engine is warm it runs perfect. the truck is kept in my garage which is kept at 50 degrees all the time. thanks for any help
john