ACCELERATION PROBLEMS

Good morning friends.
I just acquired a Ford Ranger truck 2600 motor cabin, peeked in Colombia by the Mazda, so it carries the same Mazda engine, the problem is that when I turn on the car in the morning it takes a bit to turn on it either cold or hot is the same, the other problem is that walking the first or second one, the engine is very accelerated and does not take speed new speed in third Engine and puts the engine at a thousand revolutions at a thousand revolutions, I wanted to lower the acceleration by the screw that is next to the acceleration cable but does not lower the revolutions and it is what is making me spend a lot of fuel.
Thanks in advance any help they could provide, I was looking for some manual of that type of motor and I do not find it if someone has it could facilitate it would be very grateful.