my truck is an 86 f150 5.0 4x2, when you first fire her up she runs smooth and idles almost perfect but as soon as she reaches normal operating temp she goes to bucking, coughing, bogging down etc. its so bad that i have to have pressure on the gas pedal when im at a red light or she WILL die. she fire right up after that put wat can be causing this??? im leaning towards a hot coil, any help is greatly appreciated

 

Get a Haynes manual & a digital multimeter, and follow the ignition diagnostic procedure in Ch.5.



Also check fuel pressure with a gauge:



Then check the ECT & ACT:



If they're all good, stop by a junkyard & pick up a few MAPs to swap in (same location as the pic below). If one of them makes a difference, start shopping for a new one. Stay OUT of the zone.

 

fuel pressure has been checked a few days a ago its around 30-35 psi....I will now go after on of those manuals and a MAP.
THANKS STEVE