brown91yota

my truck was hesitating really bad and started bucking and running like crap and now it just wont even start... code 14 says there is no igf signal to ecm... i have changed the cap,rotor,plugs,wires,ignitor,coil, and o2 sensor... it still says no signal.. ive talked to a couple mechanics and they said maybe distributor, or ecm... Anybody have any suggestions i am lost and getting pretty burnt out. Thanks any help would be greatly appreciated!!!