Originally Posted by mark72450
I have a 2001 F-150 that lately it will not start right up I will crank it for 5 sec or so and it will not start but today I discovered that I hear a gargle noise after cranking it so I tried to crank it again before the gargle noise and it started right up on the second crank and started fine the rest of the day this has happened 4 or 5 time in the last month. can any one help? I am thinking maybe fuel pressure regulator just guessing
Good guess. On occasion a fuel pressure problem may cause difficult starting. A difficult re-start (when hot or cold, after the truck has been stood only for a few minutes) and LTFT is persistently negative at idle, whether or not a P0171 and/or P0174 has been recorded - then suspect the fuel pressure regulator is faulty - causing fuel rail over-pressure.
If the engine is difficult to start when cold and the LTFT is showing a consistent positive LTFT - whether or not P0172 and/or P0175 is recorded then suspect that the pressure regulator is not pressurizing the fuel rail properly and the injectors are unable to provide enough fuel.
Also keep in mind that cannot crank these engines more than 4 seconds. After 4 seconds the PCM shuts down the injectors to protect the converters.