95 Ex Idle problem?

If anyone has any imput it would be appritiated. I am an transmission mechanicas son with decent backround of fixing this stuff.. i just put a new starter in 2 days ago because the solenoid was $45 more than the whole starter itself! ugh.. anyways the idle has been crap for a good 2-3 months now and i've tryed a few things but im starting to look for bigger answers. It's not fixable from: The throttle cable, and dumping any solvents ( injecter cleaner ) down the fuel tank, & the distributer is cranked all the way up. **The problem its having is low low idle, very rough at times (200 rpms) but no stalling? thinking its bad injector, ecu or timing belt but want more opinions before i go wasting money. Also almost every sensor has been replaced within last year.. to narrow this down.