Ok guys, need some help. Here are the details:
2000 F150 5.4L 2v
Truck was running fine down the highway, then suddenly as I accelerated after a corner the engine started missing rather badly. Scanned multiple times and after each attempted repair, cylinder miss would sometimes move. Here's the meat.

Check and changed all eight plugs. Checked and replace all eight coils and injectors. Considered wiring issue, so replaced all eight coil and injector connectors. Replaced all old vacuum lines and connections. Like I said, after each repair, code scan changes affected cylinder/cylinders. I do not have an expensive scanner to pull mode 6 data or to monitor engine while driving.

What's next? Need some help on what obvious issue I am missing. Next step is to pull the engine and replace with a block bored .020 over if I can't resolve this. No, this truck will not get scrapped. Its my beat up toy.

Thanks for the help!!!


Update ....

Parts Changed:
Coils
Injectors
Spark plugs
Wiring connectors for the coils and the injectors
EGR Valve
EGR Feedback sensor
EGR Vacuum Solenoid

Codes found on the ECM:
P0351, P0353, P0357, ​​​​​​​P0358, P100 (Not worried about this one)

I have tested the current going through the coil wires. I have power on every line and the ground trigger is working on every line when the engine turns over.

I am at the point now that I am almost sure that it's the ECM; or corrosion on the ECM connector on the firewall. I haven't checked that yet.

 

sounds to me like you have a bad ground, or junk coil packs

 

Checked the ground on the 1-4 cylinder head. Tight with no corrosion. As for the coil packs, tough to believe that I would have 16 bad coils. Haven't ohmed them yet, but 16 bad ones?

 

An ohmmeter can't find bad coils unless they are totally dead.

 

Might be EGR related.
If it opens to soon or uncontrolled and let's exhaust gas into the intake, the mixture becomes very lean.
Then misfire can result if the Lean Mix can't be fired by the ignition.
All cylinders would be affected.
Good luck.

 

Sorry for the late response.

 

I don't know all you've done so here is what I would be looking at.
Fuel pressure being low.
Possible dirty injectors.
Excess water in the fuel.
Intermittent power to the coils or Injectors.
A look at the Long-Term Fuel Trim Tables.
Good luck.

 

Any improvement with this? A good scanner is just about the best tool you can buy

 

Not yet, thinking I might have narrowed it down to a bad ECM.