Solved: Misfire Problem
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Junior Member
Joined: Nov 2014
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Solved: Misfire Problem
I had what seemed like a serious problem with my engine. I was having a terrible shutter at 45-55 MPH and under load. Then, I developed a rough idle. My truck is:
2006 F-150 XL, 5.4L engine
To save someone some time, the bottom line of the problem was a faulty brand new MotorCraft spark plug. I may have also had a bad COP and spark plug, which I fixed early on. My problem was prolonged by a faulty new spark plug, which caused me to chase my tail.
I bought this truck knowing that it had a shuttering problem. It would idle alright, but when I would get between 45-50 MPH, the engine would misfire badly. It felt as if I was going over a rumble strip, as someone else described it. If I let off the pedal, the problem would stop. If I pressed the pedal down hard, the problem would stop. I had this code: P0354 Ignition Coil D Primary/Secondary Circuit Malfunction. After reading through the forums, I found that the problem was most likely spark plugs or coils over plugs (COPs).
I first replaced all of the spark plugs. They did not look too bad, except the plug #4. It appears that the Ford mechanic broke it off at the last tune up and did not extract it, or he did not attempt to change it at all. I say this because this particular plug was different than the 7 other plugs. Nevertheless, I extracted it with the special tool (Lisle) and replaced it with a new MotorCraft. This did not solve the issue. It may have, in fact, made it worse (possibly because I was moving the coils and coil wires around). The truck began to idle pretty rough; I could definitely feel the misfire at idle. Over the course of a week, the idle became more rough and started feeling an intermittent misfire at different speeds (though I would always get a really bad shutter at 45-55 MPH).
I then replaced Ignition Coil D (which I think means coil #4) with an Accel coil from Auto Zone. It did not solve the problem. I then tested all of the original coils with a meter (I think only tested the Primary, not the Secondary). They all seemed to be working. I then took the old coil from the 4th cylinder and placed it in the 3rd cylinder. It did not solve the problem. I then moved the old coil from the 3rd cylinder and put it in the 2nd cylinder. I did this for all of the coils and did not eliminate the misfire.
Now, I was up the creek because I was having a misfire, but was getting no CEL.
After this, I replaced the fuel filter, cleaned the MAF sensor, cleaned the throttle body, changed the air filter, replaced a faulty O2 sensor, performed Gott’s Mod, and checked the Fuel Pump Drive Module. Still, the engine misfired.
At this point, I thought there were a few possibilities.
1. More than one coil is faulty. Must replace all of them.
2. The wires running from the PCM to coil 4 are faulty.
3. The injector on coil 4 is faulty.
4. PCM is faulty.
I tested fuel injector #4 with a meter. I tested just a few minutes after running the engine for 30 seconds. It gave me some funky reading. It would jump from 1 ohm to 159 to 70 to 12 to 35 and so on. The other injectors on that side of the engine measured between 14 to 18 ohms. I measured all of those again after the engine sat for an hour and they all read between 4 and 8 ohms. I decided to replace it with one from AutoZone. This did not solve the problem.
I figured, then, that more than one coil went bad. So, I ordered some off of Global Automotive on eBay because people on this forum had given these coils good reviews. When they came in, I replaced all of the original COPs with the ones from Global Automotive. This did not solve my problem.
Unfortunately, I was still not getting a CEL. I talked to a Ford mechanic who said what everyone else said: it had to be spark plugs or COPs. I told him I had replaced them all and he said it could be that the AC line could have rubbed through the wires that led to coils. I checked the wires and they protector around them had been burned through, but the wires were not burned (that is, there was no copper showing). He also told me that Ford had a diagnostic machine that would pinpoint the cylinder that was misfiring.
After all of the work I had done, and all the frustration that the problem had caused me, I broke down and took the truck to the Ford store for a diagnostic. The mechanic found a misfire on cylinder 3 and then moved the spark plug and COP from cylinder 3 to cylinder 2. That is, the misfire followed the spark plug and coil.
I went home and changed out the COP on cylinder 2 with one of the originals. It did not fix the problem. I bought a MotorCraft spark plug and put it in cylinder 2. Finally, the problem was solved! It fixed the rough idle and the shutter at 45-50 MPH.
The lesson I learned: Even MotorCraft spark plugs can be dead out of the box. I had ruled out spark plugs because I had just installed all new ones! Lo and behold, I received a dud from MotorCraft and that was what gave me the problem.
I am guessing the problem was originally a bad spark plug OR bad COP, which was resolved by new spark plugs and COPs. But, one of the new spark plugs created a whole new problem that seemed like the first problem!
I hope this helps someone that was dealing with the same I dealt with. In my humble opinion, save time and money by just taking the truck to Ford store for the diagnostics (it was about $100).
For reference, here are the steps I took:
1. Replaced spark plugs with MotorCraft (511 I think is the part number). I put dielectric grease and anti-seize on the plugs
2. Replaced Coil D (cylinder 4) with aftermarket COP (Accel brand)
3. Replaced fuel injector on cylinder 4
4. Cleaned throttle body with throttle body cleaner
5. Cleaned MAF sensor with MAF sensor cleaner
6. Checked Fuel Pump Driver Module, no corrosion
7. Replaced air filer with a K&N
8. Performed Gott’s Mod on intake
9. Replaced upstream O2 sensor on bank 1 (had a code for it when I bought it)
10. Replaced the original COPs with new ones from Global Automotive
11. Cleaned all coil connectors with WD-40 and compressed air
12. The Ford store replaced the torque converter a few months ago, which did not solve the problem (per the previous owner)
2006 F-150 XL, 5.4L engine
To save someone some time, the bottom line of the problem was a faulty brand new MotorCraft spark plug. I may have also had a bad COP and spark plug, which I fixed early on. My problem was prolonged by a faulty new spark plug, which caused me to chase my tail.
I bought this truck knowing that it had a shuttering problem. It would idle alright, but when I would get between 45-50 MPH, the engine would misfire badly. It felt as if I was going over a rumble strip, as someone else described it. If I let off the pedal, the problem would stop. If I pressed the pedal down hard, the problem would stop. I had this code: P0354 Ignition Coil D Primary/Secondary Circuit Malfunction. After reading through the forums, I found that the problem was most likely spark plugs or coils over plugs (COPs).
I first replaced all of the spark plugs. They did not look too bad, except the plug #4. It appears that the Ford mechanic broke it off at the last tune up and did not extract it, or he did not attempt to change it at all. I say this because this particular plug was different than the 7 other plugs. Nevertheless, I extracted it with the special tool (Lisle) and replaced it with a new MotorCraft. This did not solve the issue. It may have, in fact, made it worse (possibly because I was moving the coils and coil wires around). The truck began to idle pretty rough; I could definitely feel the misfire at idle. Over the course of a week, the idle became more rough and started feeling an intermittent misfire at different speeds (though I would always get a really bad shutter at 45-55 MPH).
I then replaced Ignition Coil D (which I think means coil #4) with an Accel coil from Auto Zone. It did not solve the problem. I then tested all of the original coils with a meter (I think only tested the Primary, not the Secondary). They all seemed to be working. I then took the old coil from the 4th cylinder and placed it in the 3rd cylinder. It did not solve the problem. I then moved the old coil from the 3rd cylinder and put it in the 2nd cylinder. I did this for all of the coils and did not eliminate the misfire.
Now, I was up the creek because I was having a misfire, but was getting no CEL.
After this, I replaced the fuel filter, cleaned the MAF sensor, cleaned the throttle body, changed the air filter, replaced a faulty O2 sensor, performed Gott’s Mod, and checked the Fuel Pump Drive Module. Still, the engine misfired.
At this point, I thought there were a few possibilities.
1. More than one coil is faulty. Must replace all of them.
2. The wires running from the PCM to coil 4 are faulty.
3. The injector on coil 4 is faulty.
4. PCM is faulty.
I tested fuel injector #4 with a meter. I tested just a few minutes after running the engine for 30 seconds. It gave me some funky reading. It would jump from 1 ohm to 159 to 70 to 12 to 35 and so on. The other injectors on that side of the engine measured between 14 to 18 ohms. I measured all of those again after the engine sat for an hour and they all read between 4 and 8 ohms. I decided to replace it with one from AutoZone. This did not solve the problem.
I figured, then, that more than one coil went bad. So, I ordered some off of Global Automotive on eBay because people on this forum had given these coils good reviews. When they came in, I replaced all of the original COPs with the ones from Global Automotive. This did not solve my problem.
Unfortunately, I was still not getting a CEL. I talked to a Ford mechanic who said what everyone else said: it had to be spark plugs or COPs. I told him I had replaced them all and he said it could be that the AC line could have rubbed through the wires that led to coils. I checked the wires and they protector around them had been burned through, but the wires were not burned (that is, there was no copper showing). He also told me that Ford had a diagnostic machine that would pinpoint the cylinder that was misfiring.
After all of the work I had done, and all the frustration that the problem had caused me, I broke down and took the truck to the Ford store for a diagnostic. The mechanic found a misfire on cylinder 3 and then moved the spark plug and COP from cylinder 3 to cylinder 2. That is, the misfire followed the spark plug and coil.
I went home and changed out the COP on cylinder 2 with one of the originals. It did not fix the problem. I bought a MotorCraft spark plug and put it in cylinder 2. Finally, the problem was solved! It fixed the rough idle and the shutter at 45-50 MPH.
The lesson I learned: Even MotorCraft spark plugs can be dead out of the box. I had ruled out spark plugs because I had just installed all new ones! Lo and behold, I received a dud from MotorCraft and that was what gave me the problem.
I am guessing the problem was originally a bad spark plug OR bad COP, which was resolved by new spark plugs and COPs. But, one of the new spark plugs created a whole new problem that seemed like the first problem!
I hope this helps someone that was dealing with the same I dealt with. In my humble opinion, save time and money by just taking the truck to Ford store for the diagnostics (it was about $100).
For reference, here are the steps I took:
1. Replaced spark plugs with MotorCraft (511 I think is the part number). I put dielectric grease and anti-seize on the plugs
2. Replaced Coil D (cylinder 4) with aftermarket COP (Accel brand)
3. Replaced fuel injector on cylinder 4
4. Cleaned throttle body with throttle body cleaner
5. Cleaned MAF sensor with MAF sensor cleaner
6. Checked Fuel Pump Driver Module, no corrosion
7. Replaced air filer with a K&N
8. Performed Gott’s Mod on intake
9. Replaced upstream O2 sensor on bank 1 (had a code for it when I bought it)
10. Replaced the original COPs with new ones from Global Automotive
11. Cleaned all coil connectors with WD-40 and compressed air
12. The Ford store replaced the torque converter a few months ago, which did not solve the problem (per the previous owner)
Senior Member
Joined: Sep 2009
Posts: 1,073
Likes: 28
From: Phoenix, Arizona
Thanks for the info.
I had somewhat of the same issue. When I did my plug change I dropped one of the plugs, before I installed it, and started to get a misfire code on that cylinder. It was easier for me to determine what was wrong since I felt that dropping the spark plug had done damage to the plug even before I installed it.
I had somewhat of the same issue. When I did my plug change I dropped one of the plugs, before I installed it, and started to get a misfire code on that cylinder. It was easier for me to determine what was wrong since I felt that dropping the spark plug had done damage to the plug even before I installed it.
Junior Member
Joined: May 2011
Posts: 3
Likes: 0
From: Virginia Beach, VA
Great write up.
I am experiencing the same misfire problem on my 2003 5.4L F150 4x4 while accelerating on a freeway ramp. The engine also idles rough. The truck is NOT displaying a CEL. I have recently replaced the Nr. 3 COP with an Autozone "Duralast" COP. All plugs have been replaced over the past 2 years with OEM Motorcraft plugs.
Should I bite the bullet and take it the Ford dealership to get a diagnostic on the engine? Thanks in advance for the assistance.
I am experiencing the same misfire problem on my 2003 5.4L F150 4x4 while accelerating on a freeway ramp. The engine also idles rough. The truck is NOT displaying a CEL. I have recently replaced the Nr. 3 COP with an Autozone "Duralast" COP. All plugs have been replaced over the past 2 years with OEM Motorcraft plugs.
Should I bite the bullet and take it the Ford dealership to get a diagnostic on the engine? Thanks in advance for the assistance.
Junior Member
Joined: Nov 2012
Posts: 19
Likes: 0
Not sure if this was your exact problem but another example Quick Tips: #31 Just Because It's New Doesn't Mea…: http://youtu.be/TOkhC4fKvn0
Senior Member
Joined: Jun 2009
Posts: 736
Likes: 65
From: Edmonton, AB
I just fixed mine... I had a slight miss at certain RPM's under load. FINALLY while driving to BC I went to pass someone and I felt power loss, sure enough I finally got a CEL showing misfire on Cyl #6. I swapped COP's on 5 & 6 but of course it wasn't occurring enough to throw a code again so I couldn't tell. I just went to the wreckers, got a used COP (to test), swapped out the one I suspected was bad and thankfully that's what it was. I drove home with no misfires. I'd imagine though if my #6 COP was acting up, the others probably aren't too far behind. I'll likely replace all 8 very soon. Plugs are fairly new on my truck so unless I had a bad one I wasn't suspecting. I've also had dielectric grease on since plug change 2 years ago and no change (although I still recommend it). It would be a bit nicer if the PCM could better detect/advise of misfires. The only reason it threw a code this time was it occurred several times in a row (most likely a tolerance to prevent false reporting).
Junior Member
Joined: Dec 2020
Posts: 12
Likes: 2
From: Wi
I had what seemed like a serious problem with my engine. I was having a terrible shutter at 45-55 MPH and under load. Then, I developed a rough idle. My truck is:
2006 F-150 XL, 5.4L engine
To save someone some time, the bottom line of the problem was a faulty brand new MotorCraft spark plug. I may have also had a bad COP and spark plug, which I fixed early on. My problem was prolonged by a faulty new spark plug, which caused me to chase my tail.
I bought this truck knowing that it had a shuttering problem. It would idle alright, but when I would get between 45-50 MPH, the engine would misfire badly. It felt as if I was going over a rumble strip, as someone else described it. If I let off the pedal, the problem would stop. If I pressed the pedal down hard, the problem would stop. I had this code: P0354 Ignition Coil D Primary/Secondary Circuit Malfunction. After reading through the forums, I found that the problem was most likely spark plugs or coils over plugs (COPs).
I first replaced all of the spark plugs. They did not look too bad, except the plug #4. It appears that the Ford mechanic broke it off at the last tune up and did not extract it, or he did not attempt to change it at all. I say this because this particular plug was different than the 7 other plugs. Nevertheless, I extracted it with the special tool (Lisle) and replaced it with a new MotorCraft. This did not solve the issue. It may have, in fact, made it worse (possibly because I was moving the coils and coil wires around). The truck began to idle pretty rough; I could definitely feel the misfire at idle. Over the course of a week, the idle became more rough and started feeling an intermittent misfire at different speeds (though I would always get a really bad shutter at 45-55 MPH).
I then replaced Ignition Coil D (which I think means coil #4) with an Accel coil from Auto Zone. It did not solve the problem. I then tested all of the original coils with a meter (I think only tested the Primary, not the Secondary). They all seemed to be working. I then took the old coil from the 4th cylinder and placed it in the 3rd cylinder. It did not solve the problem. I then moved the old coil from the 3rd cylinder and put it in the 2nd cylinder. I did this for all of the coils and did not eliminate the misfire.
Now, I was up the creek because I was having a misfire, but was getting no CEL.
After this, I replaced the fuel filter, cleaned the MAF sensor, cleaned the throttle body, changed the air filter, replaced a faulty O2 sensor, performed Gott’s Mod, and checked the Fuel Pump Drive Module. Still, the engine misfired.
At this point, I thought there were a few possibilities.
1. More than one coil is faulty. Must replace all of them.
2. The wires running from the PCM to coil 4 are faulty.
3. The injector on coil 4 is faulty.
4. PCM is faulty.
I tested fuel injector #4 with a meter. I tested just a few minutes after running the engine for 30 seconds. It gave me some funky reading. It would jump from 1 ohm to 159 to 70 to 12 to 35 and so on. The other injectors on that side of the engine measured between 14 to 18 ohms. I measured all of those again after the engine sat for an hour and they all read between 4 and 8 ohms. I decided to replace it with one from AutoZone. This did not solve the problem.
I figured, then, that more than one coil went bad. So, I ordered some off of Global Automotive on eBay because people on this forum had given these coils good reviews. When they came in, I replaced all of the original COPs with the ones from Global Automotive. This did not solve my problem.
Unfortunately, I was still not getting a CEL. I talked to a Ford mechanic who said what everyone else said: it had to be spark plugs or COPs. I told him I had replaced them all and he said it could be that the AC line could have rubbed through the wires that led to coils. I checked the wires and they protector around them had been burned through, but the wires were not burned (that is, there was no copper showing). He also told me that Ford had a diagnostic machine that would pinpoint the cylinder that was misfiring.
After all of the work I had done, and all the frustration that the problem had caused me, I broke down and took the truck to the Ford store for a diagnostic. The mechanic found a misfire on cylinder 3 and then moved the spark plug and COP from cylinder 3 to cylinder 2. That is, the misfire followed the spark plug and coil.
I went home and changed out the COP on cylinder 2 with one of the originals. It did not fix the problem. I bought a MotorCraft spark plug and put it in cylinder 2. Finally, the problem was solved! It fixed the rough idle and the shutter at 45-50 MPH.
The lesson I learned: Even MotorCraft spark plugs can be dead out of the box. I had ruled out spark plugs because I had just installed all new ones! Lo and behold, I received a dud from MotorCraft and that was what gave me the problem.
I am guessing the problem was originally a bad spark plug OR bad COP, which was resolved by new spark plugs and COPs. But, one of the new spark plugs created a whole new problem that seemed like the first problem!
I hope this helps someone that was dealing with the same I dealt with. In my humble opinion, save time and money by just taking the truck to Ford store for the diagnostics (it was about $100).
For reference, here are the steps I took:
1. Replaced spark plugs with MotorCraft (511 I think is the part number). I put dielectric grease and anti-seize on the plugs
2. Replaced Coil D (cylinder 4) with aftermarket COP (Accel brand)
3. Replaced fuel injector on cylinder 4
4. Cleaned throttle body with throttle body cleaner
5. Cleaned MAF sensor with MAF sensor cleaner
6. Checked Fuel Pump Driver Module, no corrosion
7. Replaced air filer with a K&N
8. Performed Gott’s Mod on intake
9. Replaced upstream O2 sensor on bank 1 (had a code for it when I bought it)
10. Replaced the original COPs with new ones from Global Automotive
11. Cleaned all coil connectors with WD-40 and compressed air
12. The Ford store replaced the torque converter a few months ago, which did not solve the problem (per the previous owner)
2006 F-150 XL, 5.4L engine
To save someone some time, the bottom line of the problem was a faulty brand new MotorCraft spark plug. I may have also had a bad COP and spark plug, which I fixed early on. My problem was prolonged by a faulty new spark plug, which caused me to chase my tail.
I bought this truck knowing that it had a shuttering problem. It would idle alright, but when I would get between 45-50 MPH, the engine would misfire badly. It felt as if I was going over a rumble strip, as someone else described it. If I let off the pedal, the problem would stop. If I pressed the pedal down hard, the problem would stop. I had this code: P0354 Ignition Coil D Primary/Secondary Circuit Malfunction. After reading through the forums, I found that the problem was most likely spark plugs or coils over plugs (COPs).
I first replaced all of the spark plugs. They did not look too bad, except the plug #4. It appears that the Ford mechanic broke it off at the last tune up and did not extract it, or he did not attempt to change it at all. I say this because this particular plug was different than the 7 other plugs. Nevertheless, I extracted it with the special tool (Lisle) and replaced it with a new MotorCraft. This did not solve the issue. It may have, in fact, made it worse (possibly because I was moving the coils and coil wires around). The truck began to idle pretty rough; I could definitely feel the misfire at idle. Over the course of a week, the idle became more rough and started feeling an intermittent misfire at different speeds (though I would always get a really bad shutter at 45-55 MPH).
I then replaced Ignition Coil D (which I think means coil #4) with an Accel coil from Auto Zone. It did not solve the problem. I then tested all of the original coils with a meter (I think only tested the Primary, not the Secondary). They all seemed to be working. I then took the old coil from the 4th cylinder and placed it in the 3rd cylinder. It did not solve the problem. I then moved the old coil from the 3rd cylinder and put it in the 2nd cylinder. I did this for all of the coils and did not eliminate the misfire.
Now, I was up the creek because I was having a misfire, but was getting no CEL.
After this, I replaced the fuel filter, cleaned the MAF sensor, cleaned the throttle body, changed the air filter, replaced a faulty O2 sensor, performed Gott’s Mod, and checked the Fuel Pump Drive Module. Still, the engine misfired.
At this point, I thought there were a few possibilities.
1. More than one coil is faulty. Must replace all of them.
2. The wires running from the PCM to coil 4 are faulty.
3. The injector on coil 4 is faulty.
4. PCM is faulty.
I tested fuel injector #4 with a meter. I tested just a few minutes after running the engine for 30 seconds. It gave me some funky reading. It would jump from 1 ohm to 159 to 70 to 12 to 35 and so on. The other injectors on that side of the engine measured between 14 to 18 ohms. I measured all of those again after the engine sat for an hour and they all read between 4 and 8 ohms. I decided to replace it with one from AutoZone. This did not solve the problem.
I figured, then, that more than one coil went bad. So, I ordered some off of Global Automotive on eBay because people on this forum had given these coils good reviews. When they came in, I replaced all of the original COPs with the ones from Global Automotive. This did not solve my problem.
Unfortunately, I was still not getting a CEL. I talked to a Ford mechanic who said what everyone else said: it had to be spark plugs or COPs. I told him I had replaced them all and he said it could be that the AC line could have rubbed through the wires that led to coils. I checked the wires and they protector around them had been burned through, but the wires were not burned (that is, there was no copper showing). He also told me that Ford had a diagnostic machine that would pinpoint the cylinder that was misfiring.
After all of the work I had done, and all the frustration that the problem had caused me, I broke down and took the truck to the Ford store for a diagnostic. The mechanic found a misfire on cylinder 3 and then moved the spark plug and COP from cylinder 3 to cylinder 2. That is, the misfire followed the spark plug and coil.
I went home and changed out the COP on cylinder 2 with one of the originals. It did not fix the problem. I bought a MotorCraft spark plug and put it in cylinder 2. Finally, the problem was solved! It fixed the rough idle and the shutter at 45-50 MPH.
The lesson I learned: Even MotorCraft spark plugs can be dead out of the box. I had ruled out spark plugs because I had just installed all new ones! Lo and behold, I received a dud from MotorCraft and that was what gave me the problem.
I am guessing the problem was originally a bad spark plug OR bad COP, which was resolved by new spark plugs and COPs. But, one of the new spark plugs created a whole new problem that seemed like the first problem!
I hope this helps someone that was dealing with the same I dealt with. In my humble opinion, save time and money by just taking the truck to Ford store for the diagnostics (it was about $100).
For reference, here are the steps I took:
1. Replaced spark plugs with MotorCraft (511 I think is the part number). I put dielectric grease and anti-seize on the plugs
2. Replaced Coil D (cylinder 4) with aftermarket COP (Accel brand)
3. Replaced fuel injector on cylinder 4
4. Cleaned throttle body with throttle body cleaner
5. Cleaned MAF sensor with MAF sensor cleaner
6. Checked Fuel Pump Driver Module, no corrosion
7. Replaced air filer with a K&N
8. Performed Gott’s Mod on intake
9. Replaced upstream O2 sensor on bank 1 (had a code for it when I bought it)
10. Replaced the original COPs with new ones from Global Automotive
11. Cleaned all coil connectors with WD-40 and compressed air
12. The Ford store replaced the torque converter a few months ago, which did not solve the problem (per the previous owner)
I'm having that same problem on my 2005 I just got back in the road engine shutter especially when I give her hell got motor craft plugs already but still need coil packs before I do that plug change not knowing if the plugs were even done in this.. thank you for the information, I thought it was a plug problem right from the get go!
