I have a F150 2001 4wd 5.4L with 15K miles. Generally, the engine starts up great. But lately, I have experienced a small oddity. Never had a problem starting it first thing in the morning. But, on about 5 occassions now, after letting the truck sit after driving for 1 to 5 hours, the engine would not start. At least not like normal. I would have to lay on the starter for a very long crank cycle, feeling the engine was wanting to start but not quite yet firing to let go the key. Last time it did this, I gave it a 'one pump' stroke on the gas pedal. No difference. Must time, I don't even touch the gas pedal when I crank.

The best way to describe it is like starting a engine that is flooded. You hold the gas pedal all the way down without pumping to let in fresh air and just keep cranking, hearing the engine cough to get going, then taking off. But here I smell no gas or see no smoke when it starts.

The other feeling is like when you have a weak coil, and the starter motor is taking all the amps, so to get it running you 'let go' the key just at the right time to divert the juice to the coil.

I have not done any maintenance on the truck other than oil changes (0-30 Mobile 1). I'd take it to the dealer, but it only occurs about once in 40 starts.

Any ideas?

 

I wouldn't worry about it. These engines are highly computerized and about 20 sensors come into play at start up and depending on the gazillion different variables it sometimes takes the PCM a second or 3 to get it's head straight.

I also would NOT ever push the gas pedal when starting! With computerized engine management there are only 2 reasons to ever push the gas pedal. 1.) when temps are below -20 you push the pedal 1/2 down to start. 2.) when flooded you push pedal to floor and hold till start occurs. When held to the floor for more than x# of seconds the PCM goes into a lean start map until a start is sensed.

I see this all the time where people instinctively push the gas when starting (My wife's father for example) and all it does is confuse the start and idle maps in the PCM.

Try a Coputer reset. Let it idle for 5-8 mins then go on a nice 20-30 min drive.

Good luck!

 

Thanks for the advice. I never touch the gas pedal when starting, i was just using that as a description to explain the condition. The cranking is more than just 3 seconds, its about 7 or 10. Normally it starts right up. I have noticed that there is also a bit of grey/white smoke for a couple of seconds after the engine catches. I am wondering if it isn't a fuel problem, like too much gas or choke. There are no mods to this engine at all. 15K miles and the only thing changed has been the oil. The problem was generally after sitting for 2 to 4 hours, and it would never occur after sitting overnight on the first morning start. But the other day for the first time it did occur in the morning, but only that once. I leave in New England but the temp has not been below freezing and I use only Texaco regular grade gas. I don't think this is normal, something is not happy under the hood. Otherwise the drivability is perfect.

 

I would still try a computer re-set because maybe the start up map is corrupt.

Blue white smoke is usually a sign of an oil leak into the cylinder such as bad valve guides or bad rings or in the case of these trucks the dreaded head gasket leak!

The reason it is so hard to tell with smoke out the tailpipe is that the cats on these trucks heat up very quickly and kill the bad smoke.

These trucks (all years) are also famous for putting out a little puff of blue white smoke every now and then when the engine was run for a very short time then turned off then when you restart you get the smoke. Do a search on "Smoke at start up" and/or "Blue smoke at start up"

I doubt anything is wrong with your truck and it is prolly just the PCM being weird!

Good luck-

 

I have seen this happen many times. It happens when the fuel regulator leaks fuel. But one thing I haven't noticed on these trucks is if the regulator is the vacuum type or not. So if it is the vacuum operated, I would bet this is the trouble. Take it in to the dealer and tell them to see what they can do. Be polite maybe they will help. They don't like these intermittent prob. but sometimes you can get lucky.