Wont idle 1991 Ford F250 Pickup 351 wisner Fuel injected when cold hasn't been started in a day will start and idle real good real smooth when put into gear and go to move will die then when try to start back will not start unless acelator held to floor when does start have to keep pumping acelator to run but wont idle unless pumping

Bad coolant temp sensor. This part asks as choke on FI engines. Some older FI engines also have a cold start injector. Check to see if yours does.

check the fuel pressure is this injected if so put a psi gadge on rail or just put the rubber hose into a quart jar an see if ya get a good flow
...if not could be the filter or pump....check wires to pump

h me perdio el chip de mi llabe como le puedo hacer es mustang

EGR valve stuck open or idle air control motor

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hav you check your plugs after it happens? a black plug will tell it has too much fuel, a wite plug no fuel at all, leads tours a faulty cold start injector, you can also try to keep it alive with carb or throtle cleaner if idles you not getting enougth fuel. keep in mind compresion test, and valve adjust, this engines require it has a regular service.
good luck

REplace the pump. common failure item.

first of all you have no carb its fuel injected, at least you know you have spark, now do you have fuel pressure??, is the fuel pump working?/ if you have fuel and pressure then you have to check signal at the injectors, so if you have fuel pressure and a good injector pulse the next step is to check the injectors, this may require removal, good luck

sounds like your egr valve is gummed up or bad. this is located behind the throttle body and has a single vaccum tube connected to it. if the diafram is still good you can remove it and clean it with WD 40 until the plunger works smooth

Hello. katienjoe. the fuel line from the filter to the fuel rail has a restrictor in the line its at the fitting at the rail. the opening messures 3/16 of a inch. so loaded it doesn't pull above 50 mph. you can change the line I did on mine the hot rod shops can supply what you need.

Does it have a carburetor or is it fuel injected? In 1986 it could be either way. It sounds like a carburetor with a choke problem.