1994joe

hello i ahve a 94 150 5.0 154000miles about 1 1/2 years . i was traveling from knoxville tn to leesville sc ,mountain roads, the truck spit going up hills and try to stall ,so stomp on pedal truck would take off ,and stop spiting but soon as you let off to maintain speed it would spit again, have had several trip to repair shop and repairs i did but its come back . i have put on or had put on egr and egr sensor, egr soleniod valve vaccum tubr ,ign control mod. spark plug cap , start using high test its seem to happen most 1 to 2 hrs of driving hope you all can help thank you in advance for reading