i picked up an 89' dakota 4x4 3.9 stick. did full tune and fuel filter. when i start it first thing in the morning it just about dies then idles good, and runs good when cold. but once it warms up it hesitates slightly at acceleration, and has a rough idle. ???????

 

You should probably check the throttle position sensor (TPS) and the idle air control (IAC) motor.

The TPS is located on the throttle body. As the picture shows, it is a 3-wire connector.
With the key ON (engine not running) check the output voltage (center terminal). At idle (throttle plates closed) voltage must be greater than 200 millivolts. At wide open thottle (WOT, self-explanitory) voltage *should be no more than* 4.8 volts. Voltage should increase smoothly as you open up the throttle (and decrease gradually as you close the throttle).


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Idle air control (IAC) motor. this is typically mounted on the rear of the throttle body. Remove it and inspect for cleanliness. Than, turn the key ON (DO NOT start) and watch for smooth movement of the pintle.

Inspect the throttle body for cleanliness and for any obstructions.