Mazda b2600 Engine Idle Erratic

Okay, So My Mazda Bravo Has Been A Small Project I Have Been Working On As My First Car, And Since We Have Had It It Has Had A Small Idle...

When I Start My Truck After A Cold Night It Starts Right Up But After About A Minute Of Idling At 1500 Rpm It Revs Up And Down For About A...

Hello, I Recently Did A Head Gasket Change And Now I Feel Like I Have Timing Issues. The Car Will Start But Sort Of Roughly Idle Up And Down...