2011 Expedition 5.4l 3v P0301 Cylinder 1 Misfire

[Digital_Dad]

It has a permanent P0301 that doesn't erase when codes are cleared

2011 Expedition 5.4l 3v

Started by swapping the #1 coil with the #2 coil, erasing codes and starting it up and rerunning the code reader, still get P0301, so swapped plugs between 1 & 2, erased codes ran it and reran codes got the P0301 again.

Unplugged the fuel injector while the engine was running but it didn't make a change in the way the engine ran.

Put a borescope in the #1 cylinder and a bar on the crankshaft bolt and had someone turn the engine while watching for the valves to move(checking for the infamous roller rocker / follower being popped off) but the valves moved fine, piston looks fine too.

A friend said that it could be a cracked intake or burnt valve because he put a piece of paper over the exhaust pipe while it was running and said it is trying to suck the paper into the tailpipe? this was before we put the borescope in the piston.

I am not sure what to try next or if I missed something

 

[JimR_TN]

Possibly the #1 injector??

 

[Digital_Dad]

We have a compression tester from OTC (OTC 5605 Deluxe Compression Tester Kit $94) on order that will be delivered tomorrow (Friday 1-5-24) I hate that OTC was the only compression tester I could verify would work on this truck, that set me back $140 for the kit and the adapter (OTC 5608 12mm Compression Tester Adapter $34) had to be bought separately and it doesn't even look like it's a quick disconnect. There might be others out there but I couldn't find one that said in its description that it would work for this engine the way the OTC one did. I want to test compression before pulling off the fuel rail.

 

[Digital_Dad]

Possibly the #1 injector??

We ran the compression test last night cylinder 1 = 165lbs, cyl 2 = 155-60.

So we moved on to pulling the #1 fuel injector out and rigged up a hose and battery and ran carb cleaner through it. Then we reinstalled it and it seems to have gotten rid of the misfire? Thanks for helping out!

Now she has to order a wheel off e bay because she had a leak and we finally got it off and in a tank and it is inside the actual wheel, it has a crack on the rear side. So there goes another $170 bucks. Also the spark plugs on cyl 1&2 were gapped to .55, I thought they were suppossed to be set to .40?

 

[pitdexion]

A rocker can pop off one of the intake valves. You will still have compression but that valve will not open. Remove cover and if it is, you can pop it back on.

 

[Digital_Dad]

A rocker can pop off one of the intake valves. You will still have compression but that valve will not open. Remove cover and if it is, you can pop it back on.

Put a borescope in the #1 cylinder and a bar on the crankshaft bolt and had someone turn the engine while watching for the valves to move(checking for the infamous roller rocker / follower being popped off) but the valves moved fine, piston looks fine too.

Yeah I checked for that issue right away to make sure it wasn't the issue. As you know that happens on these engines. Looks like we were lucky enough just to be dealing with a very dirty fuel injector. I was able to rig up a battery and conected a hose to carb cleaner and gave it the old DIY cleaning and put it back together so far we have no more misfire.

 

[71Rcode]

Man, you knocked out that diagnosis and fix. Good job!

 

[Digital_Dad]

Update: The P0301 came back, so we ordered new spark plugs and fuelinjectors, replaced them both and the code cleared and stayed away for about 4 days but now it is back again. So i am chasing my tail here, we did swap the coil pack on #1 to #2 just to see if it follwed the coil pack but it hasn't. IDK what to do next.

 

[Yupster Dog]

we did swap the coil pack on #1 to #2 just to see if it follwed the coil pack but it hasn't. IDK what to do next.

Check the coil pack wire harness. Check wire pin for that coil pack on the pcm.

 

[wk99]

Late post but I was getting a misfire code during startup and cured it with some fuel injector cleaner. Mind you I had already replaced the spark plugs and coil packs. Would've been a lot cheaper to just run the fuel injector/fuel system cleaner. We live and learn. Recommended to run the stuff every few thousand miles for high mileage vehicles. I have 178k on mine.

 

[Motorcity muscle]

May want to check/replace fuel filter

 

[Digital_Dad]

It has come back, we replaced all the spark plugs, all the fuel injectors and one coil pack so far. Today I'm pulling the valve cover to check the roller follower / rocker arms on cylinder 1. I will update, do you have to replace the valve cover gasket if it isn't leaking?

Update: I replaced the left side cylinder 1 intake roller follower only because it had a slight discoloration, it had no play in it but I had already bought one just in case so I used it. Also replaced the valve cover gasket.

 

[Digital_Dad]

Check the coil pack wire harness. Check wire pin for that coil pack on the pcm.

I am trying to do that right now but am not sure I am doing it right. I have the multimeter set to resistance, the coil pack wire is solid purple on one and white with a black stripe on the other. I unplugged the center PCM plug and tested the bottom right pin where the solid purple wire is and get 8.9. Then test the white with black stripe wire to the second row down from the top and third over from left when looking directly at the plug and get nothing, but when I switch to the purple wire at the coil plug the meter reads 24? I'm not understanding how that is even possible. Any help on how to correctly test it?

 

[Digital_Dad]

May want to check/replace fuel filter

It only has an in tank fuel filter attached to the pump apparently?

 

[Motorcity muscle]

Fuel filter should be on left frame rail under drivers seat

 

[Yupster Dog]

Any help on how to correctly test it?

I was talking about if the wire is connected properly, these harnesses get brittle.
I have had problems with the harness like in this video
https://www.youtube.com/watch?v=wMgKZ-AQwhM

 

[Digital_Dad]

I was talking about if the wire is connected properly, these harnesses get brittle.
I have had problems with the harness like in this video
https://www.youtube.com/watch?v=wMgKZ-AQwhM

Unfortunately these have a nice firm click and are not broken, I am a little suspect of the wire right where it meets the plastic though.

 

[Digital_Dad]

Fuel filter should be on left frame rail under drivers seat

Right in front of the tank is the evap canister and then the line runs straight up to the fuel rail?