What the heck is wrong with my F-150?
 

I've got a 2000 Ford F-150.

About a week ago, it suddenly developed a 'stumble'. I can't tell if its a misfire or a vacuum issue or what. Air filter is clean. I ran the tank nearly empty and filled it with premium and a can of Sea Foam (Thinking it might be water in the fuel). Doesn't seem to have helped.

Until yesterday, I didn't have an engine light, but heading up hill it started bucking like crazy and I got a blinking service light. I took it right to an auto parts store to use their code reader, but it comes up with nothing. WTF? How can the engine light come on, and not have stored codes? Do I need some special code reader from Ford?

Truck is drivable, and sometimes it goes away completely.

Damn frustrating.

Manufacturer specific drivetrain code. Need a ford reader to get it. Not an OBD code...

It's a ford....

i'm bettin a sensor went tits up, prolly O2 or crank position.

Which engine?
Probably, as said above, a sensor.

Best
Les

Fuel pump - and I am .03% confident in that answer.

Single or dual tanks?

Check engine light is blinking?

That's code for a misfire.

How many miles on the truck? Sound like mine when the head gasket let go. There was a cooling system to chamber breach going both ways. A well warmed up truck would leak enough water that under load, the mixture was too rich to fire.

Do you usual checks for a head gasket:
- Exhaust in coolant?
- Pressure in cooling system?
- Coolant out of exhaust pipe?
- Coolant in oil? (Send the oil for analysis)
- Oil in coolant?
- Compression check
...

Good Luck!

G

ignition coil most likely.

2000 still has the coil packs and wires, or is it already coil on plug?

Can you confirm fastfred that the blinking light is failure to fire?

G

blinking check engine light is usually missfire. it should ave stored a code though. it is coil on plug. A scanner yhat can read live missfires would be very helpful.

Well if you were in San Diego I would hook up my laptop with AutoEnginuity software as I have both the Ford and GM advanced diagnostics modules. The price with the ODB2 cable was around $350 and it was invaluable for my F350 diesel dually and the same for the HHR I have now. It will look at detailed codes and allow you to set monitors and you can record items while you drive into a file and review later. My F350 had over 350 sensor points while the HHR has over 14,000 sensor points and a LAN for god's sake!

I would suggest trying the Ford BBSs to see if anyone locally has the software or buy it as it will pay for its self after one or two uses especially if you go to a dealer!

Same thing happened on my Chev. recently. It turned out to be a bad coil for #6 cylinder.

Fuel filter?

Thanks guys. I'm leaning towards a bad coil or plug. Not looking forward to messing with the plugs on a 4.6 Ford V8 :(

I have a 2003 with a 5.4 that did the same thing. Coil packs.

I sold my 4.6 2007 F150 the week after finishing the head gasket. What a POS in terms of access / repair. The pros with a lift take the cab off the chassis for any engine work.

But no worries, plugs and coils will only be 2 hours and cut up arms ...

Good Luck!

G

Sounds like you sucked something up from the bottom of the tank. Change fuel filter and check fuel supply.

I worked on an 02 mustang with a fouled coil pack. Miss at idle. Took a timing light to each lead and found #3 erratic.

$47 later, back on the road.

jrp

This. Coil packs. Quite common. Run fine under light load. Intermittent miss under heavy load. -J

Plugs and, coils are not that awful to do. I use a 7mm 1/4" swivel on an18" extension to get the coils out. I also use a swivel spark plug socket . Do the rearmost ones first, as they will give you the most trouble. The one that is u nder the fuel pressure regulator is the hardest to remove, it usually requires twisting the coil and boot 180 deg, and still some bending to remove it. The one on the other side that is under the heater hoses, will remove some of your arm hair.
I usually replace the faulty coil, along with all the plugs, and the cop boots, as it is my belief that the high resistance caused by worn out plugs, and or corroded boots will contribute to shorter coil life. Dielectric grease is your friend here for re-assembly.