Treat

Need a little input from my Ford brethren. I have my F150 in the shop because I'm clueless what's wrong with it and they aren't inspiring confidence either. It runs fine until idling for a minute then it gently dies.

Check engine light came on throwing codes of lean in banks 1 & 2. I cleaned out the throttle body and couldn't hear/feel any vacuum leaks. I have an Airaid intake if that matters.

The dealership is saying there's 100% ethanol in the tank that's causing it. Nobody even sells that here and I've had the problem for two tanks. Basically they're clueless too.

Any help would be greatly appreciated!

jeeplover73

I just had somewhat same problem with my '04 5.4L. Turned out to be a vacuum leak under the intake manifold. I had already replaced the plugs and cops myself, as well as cleaned the throttle body and MAF sensor. Who knew?

Treat

I'll have to take a look at that. How long did it take you to fix?

Guy9smiley2

Fpdm or fuel pump itself is where I would start my diag.

Mod (Ret.)

Why?

Either you have fuel pressure or you don't. These two items are the most mis-diagnosed items that are replaced un-nessesarily. The FPDM recieves a signal from the PCM to turn on/turn off the fuel pump, based on fuel rail pressure measured by a sensor. This on/off arrangement is because Ford (and many other auto manufacturers) use only one fuel line to the fuel rails to assist in preventing vapor lock. In the past, vehicles used two, with a constantly operating fuel pump. Two lines required a fuel pressure regulator, which returned fuel on the secondary fuel line back to the tank. It was found that this lead to vapor lock in the fuel lines. Most of the time, low fuel pressure is simply a dirty fuel filter. A low fuel pressure condition will throw other codes as well as a lean bank condition.

Get it diagnosed properly so you prevent tossing money at it. Find another dealership.

Treat

It turned out to be a vac leak caused by my throttle body spacer distoring.