Is it possible that an injector is leaking minimally or slowly without being able to see it when the fuel rail is pulled. 2004 Fx4 5.4 The symtoms are the truck starts great every morning but cranks a little long and weird when its warmed up and driven and then parked for a while. It does it consistently every day. Never throws a code and the injectors are remanufactured GB from rock auto about 6 months ago. The battery is fine and all the cables are clean and tight. Once it starts its good and will restart immediately if I shut it down and restart it. I think my oil smells like gas a little but can't tell if its too strong or not. I"ve pulled my new plugs several times to check the condition and they look ok to me and are dry. I pulled both sides of fuel rail with injectors attached and turned key but don't see any leaking after several cycles. Its driving me nuts and I don't know what else to do or look for. Finding a modified fuel pressure guage set up for the non schrader valve is next to impossible. I know it could be something else but Im always leaning toward fuel related because of the symptoms. Any suggestions I would appreciate. Have put way too much time and money into this truck

 

I would think you would see a wet spark plug if you had a leaky injector or a Bank rich code... What's the mileage ?? have you ever changed COP's ? Springs and Boots..

 

Yes , did spark plugs, cops ,fuel filter, air filter and checked air filter foam etc and on and on at about 98k when I bought the truck. Now it has around 104k. All motorcraft parts. Im just wondering if I have a slow small leak that dissapates overnight which alows it to start perfectly every morning. what else would cause those symptoms? Fuel pump is new too. Starter heat soak? Weird battery starting to go even though it checks ok. I also have a hesitation while driving at 2000 rpm but no hesitation from a stand still. If Im driving at any speed and hit the gas at around 2000 it hiccups and then is fine. Could be a seperate issue. The starting thing is driving me crazy. It cranks long sometimes and other times seems weak not like its struggling but almost starts immediately with almost no cranking. Just a non typical crank then start. Very hard to explain. Somethings not right and should the oil have any type of gas smell? Sorry for the long response

 

never smelled gas in my oil...so, do not think that would be right.

 

I had what sounds to be the exact same problem, I even thought it was a leaky injector. Turned out to be the starter. Check your power connection on it, make sure its not loose or junked up.

 

I actually thought that it might be the starter or selonoid. I did get under there a few weeks ago and cleaned up all connections which were tight and in pretty clean shape but ruled it out since the truck starts strong every morning. How did you determine it was your starter?

 

I had some weird crank action a few months ago including very long crank times and it turned out to be my battery was on the way out. The first hint I got that it may had been battery related was when I started getting occasional bouncing gauges. Even if your battery seems to be ok you may want to get it load tested. The fuel system in this truck is real finicky about momentary voltage drops.

 

Mine had a pretty obvious connection issue. The power wire was loose (ish), I tried to tighten it and the threads stripped. No choice but to replace the starter then and all was well after that.

 

Will do. I think my battery is 5 yrs old anyway. I tried my best to do a volt meter load test. I have a remote start so I can actually be at the battery with the meter and start it and see how low it drops> I think it never went below 9.75 or so. I think below 9 is bad. I know that is not super accurate so I'll get it done correctly. I don't neccesarily have a real long crank but sometimes I think too short of a crank. Its weird and hard to describe...just not right . Thanks for the input

 

So it sounds like you found it kind of by accident trying to tighten the connection . It forced your hand and it ended up being the fix..... interesting. I think Im going to go battery first because I think mine is over 5 yrs old and then look deeper into the starter. Its being inspected today so I'll give my mechanic a call and have him run some tests. Thanks