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.