2009 Expedition Misfire

[wilsonsk]

I have a 2009 Expedition, 5.4, that has had an intermittent misfire for a while. It runs fine until I step on the accelerator fairly hard, gentle acceleration is fine. If I step it hard it misses and pops and either will start the CEL flashing and then turn into a hard miss for 20-30 seconds, then clear up and run like nothing was wrong or it straightens out and takes off with no CEL and then runs like nothing was wrong. It had been something I could avoid by not stepping on it too hard but I put a new battery in a week ago and it got noticeably worse, same type of symptoms, just takes less to get them started. I have gotten cylinder 1, cylinder 7 misfire codes several times as long as this has been going on (a year or better, I've been able to work around it), I swapped the coil from 1 to 2 and today I got a cylinder 3 misfire, P0022 and P0012 (timing retarded). The battery change thing is bizarre, did resetting the computer make it worse? It has since improved and runs fine as long as I don't step on it and make it accelerate moderately hard or harder. If I accelerated more slowly it runs just fine. It pulls hard from a dead stop, it really just does this when accelerating on the move. I have seen some info where the computer actually can go bad and cause coils not to fire? The truck has 174,000 miles on it, plugs were new around 120,000. I replaced all coils with new aftermarket coils and it barely ran, put the olds back and it went back to intermittently running bad.

Thoughts?

 

[07navi]

I would put more plugs in it and there might be water in the holes, (clean them out too), you did everything but get into the head holes.

 

[Yupster Dog]

I have gotten cylinder 1, cylinder 7 misfire codes several times as long as this has been going on (a year or better, I've been able to work around it), I swapped the coil from 1 to 2 and today I got a cylinder 3 misfire, P0022 and P0012 (timing retarded)

The way you describe it the wire harness for the coils sounds highly suspicious.
Inspect the harness and the wire bundle for tears in wrapping and see if it goes close to something hot.
Try with the engine running to wiggle the wires around to see if you can get something to happen. (do this at running temperature for best results)

 

[Anthony DeVor]

I have a 2009 Expedition, 5.4, that has had an intermittent misfire for a while. It runs fine until I step on the accelerator fairly hard, gentle acceleration is fine. If I step it hard it misses and pops and either will start the CEL flashing and then turn into a hard miss for 20-30 seconds, then clear up and run like nothing was wrong or it straightens out and takes off with no CEL and then runs like nothing was wrong. It had been something I could avoid by not stepping on it too hard but I put a new battery in a week ago and it got noticeably worse, same type of symptoms, just takes less to get them started. I have gotten cylinder 1, cylinder 7 misfire codes several times as long as this has been going on (a year or better, I've been able to work around it), I swapped the coil from 1 to 2 and today I got a cylinder 3 misfire, P0022 and P0012 (timing retarded). The battery change thing is bizarre, did resetting the computer make it worse? It has since improved and runs fine as long as I don't step on it and make it accelerate moderately hard or harder. If I accelerated more slowly it runs just fine. It pulls hard from a dead stop, it really just does this when accelerating on the move. I have seen some info where the computer actually can go bad and cause coils not to fire? The truck has 174,000 miles on it, plugs were new around 120,000. I replaced all coils with new aftermarket coils and it barely ran, put the olds back and it went back to intermittently running bad.

Thoughts?

Honestly in my opinion my family had a 2006 Expy XLT that had the same issue after 150K we dumped over $5500 into putting in throttle bodies (from CEL codes), a reman computer (which did the same thing) new battery, alternator, coil packs, plugs and we eventually gave up. We could never figure out the issue and neither could the ford dealer. It was our gremlin along with the rust by the trim piece in the tailgate. Sorry I can't offer any more advice than that.

 

[the hogg]

I had the exact same problem on my 2012. It would miss and pop under hard acceleration. I replaced the spark plugs and all 8 coils and it fixed my problem immediately,
I found 8 coils on Amazon for about $80.00 total. Probably not top of the line coils, but better than paying $60.00 each. I figure if one goes bad I can replace it for about $10.00.

 

[Anthony DeVor]

Yea true

 

[07navi]

I had the exact same problem on my 2012. It would miss and pop under hard acceleration. I replaced the spark plugs and all 8 coils and it fixed my problem immediately,
I found 8 coils on Amazon for about $80.00 total. Probably not top of the line coils, but better than paying $60.00 each. I figure if one goes bad I can replace it for about $10.00.

I keep a spare used one in my truck.

 

[Anthony DeVor]

Ok thats a good idea. I have a 2017 now so I would hope they fixed the issue from the 2nd gen to the 3rd gen expeditions

 

[Brent Harward]

Plugs and coils are good suggestions. And the lead about inspecting the wiring harness along the top of the engine is really good advice. I did plugs and coils to solve a similar misfire and found the wiring had been chewed on by a squirrel. Unwrapped wiring harness and soldered wires to two plugs, an injector and even the A.C. to fix it. All good now. Could've cost 100's if I hadn't found that chewed wire harness, right side top of engine.

 

[jimz]

my 08 acted the same way. Shop installed new fuel filter, that reduced the missing. I drove almost all gas out of car, added STP water remover to tank and fresh new fill up. Drives good now. I think it was all from bad gas. At least for my case.

 

[FlaRay]

Had a similar issue, changed plugs, and went with aftermarket coil packs, fixed it for a little bit, then the coil packs started acting a fool, had to pony up some cash to buy OEM coil packs, never had a issue after that.

 

[TLMFL]

Hi Wilsosk and welcome aboard,
On your battery check the wires(2) that go to the negative post. Make sure there's no corrosion between the wires and when you add the battery connector to the wires make sure its good and tight. We have had 3 vehicles not running right. Slow to accelerate sometimes or not at all. After doing this to 1 auto and that fixed it I checked the other 2 vehicle and that fixed them as well, Even though the connection to the wires was tight the corrosion was the problem on one of them.

 

[vincentrose]

Start by replacing the spark plugs and see what happens, if you are still getting misfire codes after new spark plugs, then the coils are the next suspect. Try this trick, if you are getting a misfire code in say cylinder #1, the swap the #1 coil with #2 coil, and then test drive it again. If the code then goes to #2, then you've found the faulty coil.

 

[jimz]

Worth a try. Thanks.

 

[07navi]

Worth a try. Thanks.

You could use a mustache, nice smile though.