I have a f250 4x4 5.8 automatic. The truck will start run for awhile then shuts itself off. Through research I thought it was the Idle air control valve So I installed a new one before that cleaned the throttle plates and surrounding areas. The truck started with the same result. The truck will keep starting if I shut it off before it shuts itself off. If it shuts itself off I have to turn the key off and wait. Then it will start and run for less than a minute.

Engine stalls cold or RPM fluctuates at idle up and down or dies near idle.

This problem is commonly caused by a dirty automatic idle speed control valve and throttle valve but always run a OBD2 fault code as well as the cleaning procedure. Buy a can of throttle valve cleaner (do not use carburetor spray cleaner!) from NAPA or Carquest (made by CRC chemicals) and spray it into the air intake while the engine is running, use up about 1/2 the can, engine will try to stall hold the speed up, shut it down and let it soak for 30 minutes, restart and blow out the remaining fluid, shut it down and disconnect the negative battery cable for 5 Min's to reset the base idle control. If the above cleaning doesn't cure your issues you need to have the computer controlled automatic idle speed control system diagnosed and repaired by a dealer or electronic engine control repair shop.

This problem is commonly caused by a dirty automatic idle speed control valve and throttle valve but always run a OBD2 fault code as well as the cleaning procedure. Buy a can of throttle valve cleaner (do not use carburetor spray cleaner!) from NAPA or Carquest (made by CRC chemicals) and spray it into the air intake while the engine is running, use up about 1/2 the can, engine will try to stall hold the speed up, shut it down and let it soak for 30 minutes, restart and blow out the remaining fluid, shut it down and disconnect the negative battery cable for 5 Min's to reset the base idle control. If the above cleaning doesn't cure your issues you need to have the computer controlled automatic idle speed control system diagnosed and repaired by a dealer or electronic engine control repair shop.

This problem is commonly caused by a dirty automatic idle speed control valve and throttle valve. Buy a can of throttle valve cleaner (do not use carburetor spray cleaner!) from NAPA or Carquest (made by CRC chemicals) and spray it into the air intake while the engine is running, use up about 1/2 the can, engine will try to stall hold the speed up, shut it down and let it soak for 30 minutes, restart and blow out the remaining fluid, shut it down and disconnect the negative battery cable for 5 Min's to reset the base idle control

Without any other symptoms it is hard to diagnose; could be water in the fuel or a plugged up air filter, that effects idle first, take it out and see if it idles fine, if so get a new one. Take out fuel filter and dump in a glass bowl and analyse for water... get a new one... Is it different when the engine i hot or cold?

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Replace the ignition module and that should take care of the problem.

SOUND LIKE IDLE SPEED CONTROL.ENGINE IDLE SPEED TOO LOW.SCAN IT CHECK FOR FAULTY IDLE SPEED CONTROLLER.

idle is set at factory but if the idle air control valve is bad it won't idle right also if the throttle position sensor is not working right it won't idle right a diagnostic scan should be able to determine which one is needed.

First buy the alldata subscription for your unit and read the engine power management system, once you understand this then you will see you don't need a scanner, you can code out if it's a engine problem then read the codes itself with a paper clip. Then once you get the codes post them here to get a better answer, the more information you can provide the better the answer you will get. A digital test meter will be better than a scanner. Without understanding the engine management system you won't be able to fix it without replacing a lot of parts.

Have you changed your fast idle valve or air idel control valve I would change the air idle valve because it is the one with an electric sensor.

if it dies when it comes back to a idle check the idle air control motor and passages in the throttle body