94 ford e-350 w/ 351 missing when motor gets hot .

ignition module , that the coil packs sit on ,was the problem on my car. had the same symptoms .ran fine till it warmed up then it started missing like crazy

clean the maf sensor

is the car running hot? some cooling fans never come on going down the road because the air comjng through the front of the vehicle keeps the car cool enough that it doesn't need to come on. but if it is overheating then you may want to check the cooling fan relay.

more than likely it a a cngine control module issue. in 1994 i beliee it is on the side of the distributo..about 10 wires going to it..once hot you would lose spark, once cool would start again

i had the same problem after my 94 limited overheated. check the heads they tend to warp when overheated. are you loosing any fluids

Take the distribuder bolt loose (on the block) and turn it eather was with it started if you turn it the wrong way it will run worse or better

check thermostat

unplug the injectors 1 at a time to listen to change in the way i runs,locate the cylinder that doesnt really change and inspect the plug,wire and if good then it may be a dirty or clogged injector,try addind seafoam to the gas and drive it for a while,it may smoke for some time but it should clean the injectors and valves really good.if it used oil alot before it may be carbon on the valves which seafoam helps clean them or you can squirt cold water in a spray bottle into the intake while running and the water explodes the carbon off the valves but it can not be really hot or damage to the valves will happen

The camshaft may be worn or the lifters .that explains the missing when you run it at operating temp.By the description of the oil. the reasomn the canmshaft wore out and the valve lifters is because the oil was not changed on a regular basis.

Your engine coolant temp. sensor is going bad. What happens is that your engine computer is receiving a bad signal from the ECT sensor and it thinks it's 40 below. An example is it basically slams the choke shut if it had a distributor. When it cools off, I'll bet it runs just fine.