Betcha your FPR has a leaky diaphragm, it's sucking fuel down the vacuum hose.

 

Give it a fresh fuel filter if you haven't done that. only 12k on an 03-thats barely 1000 miles a year.. lots of old gas..

 

Fuel will evaporate overnight on the paper... If you checked it right after priming and a few minutes later and so on, your probably fine. But if you just set it up, primed it and walked away until the next day, if anything leaked you wouldnt see it.

 

Byron,

Just randomly came across this thread while looking for info on the Raptor.

The truck did this a few times with us as well. I honestly think its just a normal Ford problem, my old 2000 3.8 Mustang did it as well as my uncles Marauder.
I wouldn't worry about it.

FYI- The truck has had multiple bottles of fuel injector cleaner ran thru it already. Also had a can of STABIL in the fuel when you bought it.

-Bryan

 

No its not a ford problem. all my ford engines start first time every time. Minor fuel flow problem. Vehicles with that kind of low miles can have issues like this not a big deal just needs a little shaking off the cobwebs..

 

yeah i dont think it is a typical "ford issue".

Bryan any background you can provide would be helpful.

so i put it back together last night, changed the fuel filter, cleaned the IAC. time will tell if things are fixed although i doubt it.

next step for me i think will be to monitor the fuel pressure at the rail. after that i am running out of options and may need to take it to a shop.

 

^^^

Pull the vacuum hose off and see if there's any fuel in it........................

 

anyone have a diagram or photo?

 

I'm feeling an IAC problem as mentioned and would replace the fuel filter too. Just for grins, disconnect your battery negative cable and clear the KAM. Disconnect, turn on head lights and tap the brake pedal a few times, re-connect. See if this helps.

 

What you do is check your running fuel pressure, then pull the Red line on the regulator to check the diaphram. That's what glc is referring to, ie, -FPR (FuelPressureRegulator).

You could have a failing fuel pump. It's not an injector IMO because it starts fine after 15 hrs of sitting, but doesn't occasionally after 8 hrs...

Also, as mentioned, - The IAC. When you clean the IAC, you have to work the mechanicals/plunger back and forth while cleaning, then work in WD40 w/compressed air or your really not doing it much good. Ford has the IAC as non-serviceable. But, you can service them as described.

So, fuel pressures first at this point. with and without reg.

 

I've ran the cheap $49 autozone IAC with out issue. I'd just get one of those and be done with it.

 

things i have done so far

#1 44k in the tank (have 100 miles on it)
#2 did injector leak test with paper. (no leaks) checked every few min in the first hour then left it overnight.
#3 replace fuel filter (old one seemed to flow fine with no obstruction once removed)
#4 cleaned the IAC with carb and choke cleaner. let dry / evap. then worked wd40 while moving the shaft / plunger. movement seemed normal before and after cleaning.


things to do next
#1 test fuel pressure and regulator. (if i pulled a vacuum on the regulator and it held without leaking would that confirm operation?
#2 do fuel pressure leakdown test.
#3 clear the KAM


the thing that has me scratching my head it this... anything that typically points to a hard restart typically wont fix itself.

so if it sits for 1-8 hours it has a hard time re-starting. if it sits overnight it corrects itself and starts fine in the morning. leaving work friday may hold a important clue, when i held the throttle wide open on the 2nd restart it popped right off (although leaving a cloud of smoke). this tells me that i have residual fuel somewhere that is getting burned off on start up.. or the engine is getting flooded during the 1st 7 sec crank and fire / stumble.

 

Your IAC is toast. Never use carb cleaner on that. You have a plunger boot and rubber seals that carb cleaner will eat right up. If it's working at all, it's doing so poorly. I'd replace it now.

 

for future reference what should be used?

who carries good replacements? should i get ford?

 

carquest and napa carry a premium quality whatever that means. i will check with ford and if OME is not much more i will probably go that route. at least we can fully rule out the IAC with replacement. i will purchase tomorrow and get it installed after work.