I got a 1988 f250 with the 302 5.0 small block and my problem starts when I first start it, it starts up will die out if I don't give it has right after then jumps up to about 1200 rpms and will sit there if I let it if I tap the gas it goes down and sits at 900 but if I hit the gas hard it sputters and doesn't jump on it like it should and when I drive it it'll bog down off the clutch in 1st and 2nd gear and after that it will be fine but if I drive around for say 30 min if I come to a stop and try to go again it'll big down and shut off and won't start until being let sit for about 10 to 15 min

 

I have replaced my Ecu due to water damage cleared up for a day or 2 I've replaced my fuel pump, fuel filters, o2 sensor, throttle position sensor, have new plugs new wires and new distributor cap