1995 Ford F350 Acceleration

Cold start engine idles but when pressing the accelerator the "check engine light" comes on and will not accelerate. Then after pumping the accelerator it accelerates for short distances then light comes on again and the engine idles but does not accelerate. Then when shifting often light will again come on and acceleration ceases but engine continues to idle. I also noticed if having to use my wipers, that when the wiper returns to the rest position the "check engine" light comes on and acceleration stops and idle continues.