2006 Expodition 145000 miles. New Plugs, Cops, Oxgen Sensor, Speed Sensor, Fuel Filter, Air Filter, Both VCT changed, Mass Air Flow Sensor, Thro ttle Body.
Will Misfire on load. Changed to another new plug and cop on that cylnder then moved to another cylnder changed those then it moved to another. I give up.

 

What brand plugs and cops are you using? Have you tried any injector cleaner in the gas? Techron is the best.

 

All parts are Motor Craft

 

 

codes?

 

First was P0304 so I put another new plug and cop put it under load again P0306 then I put another new plug and cop then P0307 put another new cop and plug now it's P0302 remember I just changed all the plugs and cops 2000 miles ago plus all the other items.

 

Did you happen to leave a ground wire loose? You're getting misfires on #4,6,7 & 2. I'd look at a schematic and see if there's a wire connection where all of the signal to the COPs come together.
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Thank you I will check. Question I would have is how would it run fine for 2000 miles then start doing this. I'll get back after I checked the ground.

 

If the bolt or nut that secures the ground terminals worked loose it could cause something like this.

I could be way off but it seems like something upstream from the coils that's causing the issue. I'd check all the wiring for something loose or damaged.

 

Could be the fuel injectors like glc suggested. Techron or Gumout for high mileage engines.

 

Checked the ground and followed all the wires back to the CPU unclipped all connections put dial lithic grease in them looked for any damages to wires all good. Cleared the code took on test drive it gave code P0302 as before. I guess I'll change the plug and cop on cylinder #2 now.

 

If the plugs and coils are new changing them won't do anything other than thin your wallet. Have you checked the fuel rail pressure when it's under a load? If the filter is getting clogged it could cause something like this. Since the problem seems to be moving around I would suspect a fuel delivery problem more than an injector acting up. Changing the fuel filter and checking the rail pressure will let you know if there's a problem there. Injector cleaner won't hurt anything either.

 

At idel it's 25 and goes up to 40 when I give it fuel and has new filter

 

That may be a bit low - I'd check the FPDM for corrosion.

 

I want to say there should be around 40 psi at idle on that truck. Do you have a way to check the fuel trim levels or the O2 sensor values? If so check them and figure out if you're running lean under a load. Also, look up the specs for the fuel pressures. It's starting to sound like you have a fuel delivery issue.