I have a 2000 F150 5.4L Sometimes she starts sometimes she don't???? I just changed the plugs a week ago and it fired up. Now after about a hundred mile it sometimes starts and sometimes doesn't Air temp doesn't seem to matter it's been above 36 F. It cranks but doesn't seem to want to fire. Fuel is Reqular 87 octane. I crank until the battery goes. What next battery or fuel? Any electric things I should check first? I pulled some of the plugs and they look good still.

Help

 

Starting problems are IMO the most complex problems to troubleshoot. Especially with EFI. It could be a larger number of things. The basics suggest (1) compression (2) fuel (3) ignition and even (4) air.

Just check everything on the list. It is long and tedious. If you have been maintaining the vehicle, you should rule out some things.

Starter and starter relay and battery. (seems u are getting beyond that)
Coil, distributor cap and rotor and plug wires and plugs
Fuel injectors and fuel pump and fuel filter. Bad gas? Gas lines? Are the plugs getting wet with gas?

It could also be a bad computer, I had that happen once. Stalled the car in the middle of nowhere. Nothing worked at all. (probably not your case)

And more.

 

The very next time it does this, check for spark and fuel pressure. This will help you narrow down the cause. Did you put a bottle of heat in it earlier this winter or recently; this will rule out water in the gas.

 

Ok good to know. I just bought the truck and it has 76500 miles on it. So now I fel like a shmuck. I haven't been the one maintaing it until now. When it starts it runs great. The air filter looks good. It gave me the same trouble with premium fuel. Most likely not bad gas. Maybe not getting fuel? Plugs do seem dry but it takes some time to get them out. With compression why would it sometimes start and sometimes not based on compression. It cranks over how would I check the compression? Now I just want it to start so I can get it to a mechanic. Anybody know a good ford Mechanic around Lansing MI.

 

Yes I did put in fuel treatment to keep water out. One bottle quite a while ago.

 

Next time this happens(not starting) try pushing the accelerator down just a little bit. If it starts but will not idle without your foot on the gas, you most likely need a new IAC(idle air control) motor.
It is located on the throttle body. It allows air to bypass the closed throttle body at idle. Its job is to adjust idle speed and it sometimes will get stuck shut not allowing the truck to run.

 

You can check to see if you have fuel pressure quite easily.
On the passenger's side fuel rail, above the injectors, there is a valve cap like a tire has on it. Under there is a valve like a tire has. You can press down on the valve with a small screwdriver or whatever and see if there is fuel pressure. Make sure you hold a rag over it while you do that and keep your face away. The fuel in there can be under quite a bit of pressure and blows out pretty far.
Do any lights on the dash flash when it wont start or do they just turn on and off like normal?

 

Well I scratched my head and decided I wanted the truck to start ASAP so that silver and chrome Ford perched up on a flat bed tow truck and tomorrow the Techs down at the shop will let me know how bad it is. I'll let everyone know what it was. Thanks for all the help all of these tips are good to know.

 

Tow to dealership $75.00 . Estimate from dealership $75.00.
Set of two keys $209. The dealership told me the theft system was set off and my keys were no good so they programmed two new keys and reprogrammed an old one I had. Did they B.S. me cause it feels like I grabbed my ankles and cried uncle?

 

That could happen. These PATS things can be over looked sometimes.
Jimmy

 

What can I do so that it won't happen again? They said it may have been caused from when I changed the plugs and reconnected the battery causing a power surge.