2001 Ford F-150 4.6L V8

So for the past 2 months I have been having an intermittent crank no start problem with my truck. The truck will run fine for a week or so then when I go to turn it on in the morning and it will crank but not start. I leave it alone for a couple of hours, comeback and it starts right up. It does this once or twice every 2-3 weeks. Once it turns on it runs good and won't do it again for a while.

Was told it was fuel pump problem so I replaced the fuel pump. Truck worked good for a week before it started happening again. The mechanic said it is the fuel pump again. Haven't been able to test the fuel pressure when I am having the no start problem since I don't have a gauge.

The only code I have is a P0430 - Catalyst System Efficiency Below Threshhold (Bank 2)....

Does anyone have any idea what it is/could be...

 

You don't necessarily have to have a gauge - you can tap the Schrader valve on the rail and see if fuel sprays out.

When you turn the key to ON, do you hear the pump run for a couple seconds?

You need to get that cat issue fixed, it may be clogging up and the backpressure will do some nasty things to your engine.

 

Yeh when the truck is not starting I can still hear the fuel pump turn on when i turn the key.....the truck is running fine right now so the fuel system is working right now so I will have to wait till it starts messing up again to check I guess

 

When it doesn't start, try holding the pedal down slightly - if that doesn't work try flooring it. Holding it down a bit will bypass a stuck IAC, flooring it will shut the fuel off if it's flooded.

 

So I filled the truck up yesterday and this morning it wouldn't start. I tried as you said holding the pedal down slowly, which didn't work, then floored it and it turned on. I also forgot to mention that it usually messes up when I fill the truck up. Once it gets down to 3/4 tank it is problem free till I fill it up again.

 

That sounds like leaky injectors. Need to get that fixed before it hydrolocks. The leaky injectors can also trash the cats.

Another possibility is a problem in the evap system, dumping fuel into the intake. Next time you fill it, don't top it off after the nozzle shuts off, or only fill it to 3/4.