Rep Power: 0

This car has had the head surfaced.Replaced time belt , water pump, idler, iac, spark plugs, wires, vacuum lines and fuel filter. TPS checked no dead spots correct voltage open and closed. Map sensor checked put. Injectors are clean. Check time belt again and it is right were it should be. After the engine is warm with or without a/c on the idle will drop 300 to 400 rpm, it varies. Sometimes after a few seconds it will go back to about 750 rpm. The engine always seems rough at idle and it gets about 25 mpg on highway with a/c on and 28 to 29 with a/c off. I do not know where to go from here. Any help would would be appreciated.

 
Rep Power: 812

try the idle learn procedure. run car to operating temp, turn off, disconnect battery, reconnect, start car, let it idle for 10 mins without using any accessories or pressing gas. turn car off and then back on. go for a drive. see if it fixes the idle drop.

 
Rep Power: 0

I did what you said. I did the idle learn with the engine warm and it still drops with no accesories on. I drove it for about 15 minutes then turned the a/c on (it was hot yesterday too) and the idle droped ike it did before. It acts like it is missing, no codes. All wires have fire it just sems maybe the spark is not hot enough and I can't figure this out. Thanks for the suggestion.