You may have more than one problem. I think you need to set up the throttle body adjustments according to specs. It sound as if you may have "fiddled with it" and you will not be successfull solving any problems until this is set up correctly. This involves setting the home position of the throttle, adjustment of the TP switch position and then base idle speed adjustment. At this point if there are no faults the idle on that engine will be at 750 rpm and 900 with air on. This is controlled by the idle air motor NOT adjustment of the throttle body.

Further diagnosis must assume that plugs, wires, rotor, cap etc are all in good condition, throttle body clean, no vacume leaks.

Underhood or and engine temp can affect some problems.

New fuel filter will not be clogged.

What is the idle speed?

Suggest you review the 700/900 FAQ section for lots of good information. Your engine is the same and for all practical purposes the information there is valid.

Good Luck! Post results or questions.