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O.T. 03 F250 no start mystery.

Bobnotthecat

Cast Iron
Joined
Jul 5, 2009
Location
S.W. PA
Hello, Sirs,

I have this F250 03 model truck that has recently developed a strange starting problem. Truck starts in the morning and every time until after or right at noon. Then cranks like crazy but absolutely will not fire. The first time this happened I had it towed to a local garage where it sat over night. Next morning I get a call from the mechanic saying that it started right up and that he/they couldn't find anything wrong with it. It ran every time it was tried. So I left it sit until I needed it again. Fired right up, sounds great and has plenty of power. I ran my errands then stopped at the tire shop for new tires. When they went to pull out of the garage at noon, + or -, it wouldn't start. No codes had been set on OBD. I told them that it would start in the morning and of course it did. Yesterday afternoon raking and burning leaves I decided to move it but again no start. This morning I went out at 7am and viola it starts up and every time till the next time I need it.

I can't find anything wrong with it. It has 93000 miles, very clean for it's age and has been well cared for. So I'm asking yinz for some clue as to what to look for or tell me of a similar experience and what was done to fix it.

Thanks for looking,

Bob....not the cat.
 
Assuming it's a diesel?? .........has it got a solenoid on the injection pump? ......if so they can mess you about big time (well the European makes can)
 
If it is a diesel and it's a 6.0 then you are in good company with the hot no-start issue. The problem is with the HEUI injection system. There are a bunch of O rings in the high pressure oil supply that will slowly begin to fail over time. When the engine is hot they leak just enough that the injectors won't fire. The cure is to replace the dummy plugs and stand pipes with updated versions that have better seals.

You could do a youtube search on diesel tech ron and hot no start. Lot of good info on how to diagnose. If your tech is not familiar with 6.0s they can have a lot of trouble figuring this out.

Good luck.
 
If it is a diesel and it's a 6.0 then you are in good company with the hot no-start issue. The problem is with the HEUI injection system. There are a bunch of O rings in the high pressure oil supply that will slowly begin to fail over time. When the engine is hot they leak just enough that the injectors won't fire. The cure is to replace the dummy plugs and stand pipes with updated versions that have better seals.

You could do a youtube search on diesel tech ron and hot no start. Lot of good info on how to diagnose. If your tech is not familiar with 6.0s they can have a lot of trouble figuring this out.

Good luck.

The trick to hillbilly fix that is to put a starter from a new 6.7 (from wrecker) on.
Then the sucker will spin over 2x as fast and build more pressure than needed to start.

But not applicable to the 5.4

Sounds like fuel pump to me.
 
Ivan will certainly fix it, he guarantees it. He's got a YouTube channel where he shows his skills at diagnosing difficult auto problems. However, he lives over at State College so you might have to drive a ways to meet up with him.


Pine Hollow Diagnostics: Pine Hollow Auto Diagnostics - Home


Ed P
 
Just a bit of info i would stay well clear of anything with HEUI system on it. It was a CAT concept that they put into production and it failed.

Just not a good reliable design.

Some engines need to meet certain criteria to start. Like having oil pressure built up, spin speed. while not knowing your particular engine i would take it to a person trained in that specific engine..who works on them all the time.
could be as simple as a incorrectly set speed sensor.
This board may give you ideas but you need some gear to fault find as well and by the time you buy that it may be cheaper to take it to a guy who has it and who knows that engine and just pay the man.
 
When a gas motor won't fire, there is only one question to ask at first.

Spark or Fuel?

Then that leads you down the rabbit hole of what the actual problem is.

Ok... sometimes it not either the spark or fuel, but I would assume that since
it does eventually start, that its not some crazy mechanical thing.

If you don't want to check a plug, which might be a pain if its a coil per cylinder
thing, or it happens to be a Ford, where the plugs either won't come out, or won't stay in.
Just blast a bunch of starting fluid down it. If it has spark, it'll kick over for a bit.
 
Some of the Ford diesel had an injector cracking pressure that required a certain RPM during cranking. You could hit a few RPM below and it wouldn't go even though it sounded like it was cranking fine. New batteries needed. As for the 5.4L....who knows? lol
 
It is a Ford. No fob just an ordinary key.

Always starts after a good nights rest!

Starts even when the engine is warm early in the day but not in the afternoons.

Guess I'll just have to pack a lunch and an overnight bag when I go to the store.

Thanks, guys,

Bob....not the cat.

PS:
Please don't give up yet keep thinking.
 
Check:

fuel
spark
wiring
Camshaft position sensor ...............or crank sensor...........
Oil temp sensor.......................my ford did a hard start for oil temp.......
air filter

Newer motor computers check the ohm resistance of plugs & wires............. I would suggest that you do the same.

loose spark plugs ................a coworker had a ford motor shoot out some plugs.............. bad threads in the heads........
 
They fixed that plug problem about 2003. Then the plugs break apart when removed and bits stay behind in the cylinders. You may have to pull a cylinder to get them out but they make special tools that may work so the head can stay on.
Bil lD
 
My Toyota T100 won't start after sitting for half an hour or so after shutting it down after it was up to temperature.

The ECU thinks the engine is a different temperature than it is and doesn't give it enough air or fuel or whatever to get it going. Pressing the gas pedal while cranking fixes it.
 
OK here's a quick test.

Next time you have it in the no-start mode, unplug the mass flow air sensor.

If it starts then, the engine control computer is implicated with an intermittant failure.

I have a ford ranger that would show these symptoms, until it finally became non-intermittant.

Unplugging the mass flow air sensor puts it into a limp-home mode and it would start then.
I figured the MFA sensor was bad, replaced that, but no joy. A new ECU fixed the problem.
 
If it will not start remove the gas cap then put it back on. I would check the fuel pressure at the rail. How long since the fuel filter was replaced? Does it have a distributor and rotor.
Agai, can you hear the pump run when you turn the key when it is hot. Does it take more or less time to come to pressure and switch off.
Bil lD
 
If it will not start remove the gas cap then put it back on. I would check the fuel pressure at the rail. How long since the fuel filter was replaced? Does it have a distributor and rotor.
Agai, can you hear the pump run when you turn the key when it is hot. Does it take more or less time to come to pressure and switch off.
Bil lD
Second the gas cap trick. My Toyota has similar quirks. Do that and turn key with foot all the way to the floor and immediately take foot off gas, it somehow tricks the air/gas ratio enough to let the vapor locked gas burb. It’s a fuel system temperature not engine temp.
 
The gas cap is because my first ranger would not run right after a longish trip until the cap was removed. I could hear air rushing into the tank. The vent line from the tank to the carburetor was plastic and it was too close to the exhaust. It had melted a little and closed but still in one piece just necked down. I replaced that section with metal and fixed that problem. It probably had a pinhole size opening so it could equalize the pressure overnight after a short trip. Or the cap leaked a little or something else leaked a little air into the tank.
Bil lD.
 
Its probably the crank sensor, but you should actually diagnose it. There is a schrader valve right on the rail, very easy to check fuel pressure. You can hook up a gauge and just leave it on while you drive around. As far as the crank sensor you would need a scanner that will show live data.

If it was my truck I would just leave my scan tool plugged in, if live data shows no cranking rpm during no start its a crank sensor. Never seen a mod motor throw a code for the crank sensor.
 








 
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