rough idle
 

my 92 capri is idling very rough, once accelerated past 2500 smooths out. any ideas? car was empty of gas for a couple of months with battery also unhooked ,pcm and tcm were changed out at that time also, is there a learning time for the on board computer? and how can that be reset to factory default?

pulling the battery off for a few minutes should reset the computer to default. I doubt very much that it's a computer issue. It sounds more like a distributor cap and rotor or plugs issue. possibly fuel injectors gummed up. relearning of idle shouldn't take more than 4 full temp cycles, but some cars take upwards of 8 to 12 cycles. a cycle is getting it up to normal temp and running for a while and then cooling off completely. also, check the timing and make sure it's spot on where it needs to be. That can really mess with the idle. you may also need to clean out the throttle body with some carb/throttle body cleaner.

Maybe you can change the fuel filter. since it was low or out of gas, it allows the crud in the bottom of the tank to be disturbed and sucked through the pump and plug up the filter. Maybe clean the IAC, too.