Information on the truck, 2003 F150 4.6L that is experiencing a no start problem. Last night i changed the battery in the truck and now it is cranks but won't start. Today i have changed fuel pump, spark plugs, starter solenoid, and OHM check all the COPs. I can get the truck to start if i hold the gas pedal down when cranking, but once started i have to hold the pedal to keep the truck on as it will not idle, also once it starts it runs extremely rough. Does anyone have any ideas how to fix this issue?

 

If you hold the gas pedal down while cranking? I believe that shuts off the injectors. Was anything wrong with the truck that relates to this before you replaced the battery. I'm curious as to why you threw a new battery in, then when it wouldn't start you replaced the fuel pump and other various parts.

 

Last night i when to the store, came out and truck wouldn't start just a single click when i turned the ignition and the lights in the cab would dim out , so i threw a battery in it.

 

My guess is the alternator. Its always in cahoots with the battery.

 

Gotcha, and just to confirm, it does crank now but will not start? Have you checked over all the requirements an engine takes to start, such as air, fuel, and spark?

 

Correct the engine cranks but don't start. im pretty sure i have check everything over.

 

Check your computer connection. My 98 truck would not start just turn over and that is it. I checked everything and finally decided to check computer. The computer terminals were really dirty. It had like green crust on it. I got a q-tip with alcohol cleaned it and it solved the problem. Check it, you never know.

 

IAC for one, it won't start without the pedal or idle. That's IAC.

The hesitation , - I'd fix the IAC first (if that's the problem), then see what you got.

 

Tried this didn't change the issue.

Replace the IAC still no change.

 

Update i have narrowed it down to a spark problem 3 of the 8 COPs are getting power, the driver side cops are not firing including the passenger rear COP the first three on the passenger side are working.