Any Ford mechanics on board...misfiring issue

[Huntindad]

My son came home from college for thanksgiving and after I asked him if the truck was running ok... he said, Oh yeah, i was gonna tell ya, it has been running bad and says check engine. Geez...

I went to Autozone and it said the cam position sensor was bad and # 5 cylinder was misfiring. Along with an EVAP issue.

It is a 2002 F150 with the 4.6 engine. Had OEM platinum plugs and coils replaced 60K miles ago. Truck has 153K miles on it.

I ended up taking him back to school as I thought I had it corrected, but nope...

after the autozone Cam position sensor along with a coil did not fix the issue I got a ford OEM cam sensor. helped a lot. now to my delima...

It starts fine and idles fine. At about 45 MPH and RPM of about 12-1300...if I accelerate gently, it misfires quite a bit. If i give it enough gas to downshift and raise RPM to 2000, runs smooth as can be...... WHY ? bad plug?

I disconnected the battery to clear the codes and check engine light is not on anymore. IDEAS ???

thanx,

[tx_basser]

You get that error when the trans slips. Got a similar error on a dodge and flushed the tranny and put in a quart of Risolene. That got rid of the problem along with selling it.

[Puggy625]

Sounds more like a torque converter to me. But, I don't even consider myself a shadetree mechanic.

[Huntindad]

I don't like where y'all are going with this. Hadn't thought about the tranny.... sure hope it ain't that.

[ktjones]

What are the codes that are coming up? Had a similar issue, although different vehicle altogether - it was the MAFs (this car has two). KJ

[RifleBowPistol]

Probably a bad coil. I only buy what used to be Borg Warner coils for those things, Borg Warner is now Standard Ignition. They have lifetime warrantee, the Motorcraft coils do not, they all have the potential to fail. My 2002 F350, had it's first bad coil two weeks after I got it, I special ordered it, took possession of it the day it got to the dealer. Then a week or two after the first coil, I had another bad coil. Those two coils which are the rear two coils, I have replaced at least once each since. Kind of surprised at the coils being bad as early as they were, but it happened. They usually last a lot longer than that, but I found when I drive through water deep enough to splash up on the engine, it won't be long, before I have another bad coil or two.
The idea it's torque convertor shudder is a possibility, that does happen or we used to see it regularly. But for many years now, it's been pretty much a guaranteed thing, that when I have one that seems like a miss, it has a bad coil. I finally found a way of finding bad coils, too often there are not any miss fire codes, even though the engine has a miss most of the time, for some reason the computers regularly don't set a miss fire code. So I just pull all of the coils and inspect them, any I find that look suspect, I replace, so for 100% of the time, that has gotten rid of the miss the vehicle had.

There are other possible causes of a misfire. It could be lean. Lean misses are usually caused by vacuum leaks. The vacuum hose that goes to the PCV valve, usually has two rubber ends on it or a rubber elbow, that will get soft and gummy. When that happens, it will suck a hole in the hose. I would inspect the vacuum hoses first, make sure they are all good, the full length, any soft or gummy hoses, hard, brittle hoses replace. You could also have a EGR valve stuck open from being carboned up. Also the intake gaskets and plastic intakes are known to leak. Those will all cause a lean miss.
Good idea while looking for theses problems, to clean the throttlebody and IAC valve out very well, removing them and thoroughly cleaning them is best. Clean the throttle bores, front, back and the edges of the throttle plates, with carb cleaner. clean out the IAC valve also. Use some MAF cleaner or brake parts cleaner and clean the elements of the MAF sensor. Only use something that will dry fast and leave no residue. Be careful not to break the elements, only spray them off, definitely spray them down, if there is any gunk on either element. Those last things, will just make the truck run better, not fix a lean miss or a ignition miss.
On inspecting the coils, there is a blade up in the bottom of the coils, that looks like a male blade terminal. You need to remove the spring from the bottom of the coil, without damaging it. I pull and twist it gently, eventually it will come out of the bottom of the coil. Once you have the spring removed, inspect the blade up in the bottom of the coil. If there is any corrosion, green, gray, brown, replace the coil. What I have found happens, is water gets down in the spark plug hole and accumulates. Then when the engine is hot, that water turns to steam, which goes up, if there are any leaks in the bottom of the coil, the water gets up inside the coil. Once the water gets into the coil, it will cause corrosion, which you will eventually see on that blade on the bottom of the coil. I have found that is the only way to determine if a Ford mod motor coil is bad or not. Don't be surprised, if you have three or four coils with various color corrosion on the blades.
I have gotten many vehicles other people could not find the cause of a miss and had given up. Because they were looking for a miss fire code. First thing I check for large vacuum leaks, they pull all of the coils. I always find the cause of the misfire. There is one more thing that causes misfires with those particular engines, that is the spark plugs getting blown out of the head. Once it completely blows the plug from the head, it will break the coil and you will get a loud noise from that cylinder. My truck has blown two plugs out of the heads, both times, I got a intermittent miss, before it completely blew the plug out of the head. I had to put heili-coils in both heads. My truck has 269,000 miles on it. Many guys will tell you the heili-coils don't work or won't hold. I have had very good luck with them. I also have two different spark plug thread insert kits. The one that looks like the best design, is the only one, I have had blown out of the head, after installing them. Hope you don't have plugs coming out of the heads. Checking all of your spark plugs every once in a while is a good idea. They will be loose, before the completely blow out of the head. When you find one that is loose, like someone forgot to tighten the spark plug, it likely is about to blow the plug out of the head. I have found plugs that were loose, tightened them, then within a week the same plug blew out of the head. It was just a case of me finding the plug right before it completely blew out.

On the torque convertor shudder, if that turns out to be the case, you can buy additives to put in the fluid, that will usually cure the shudder. For years, Ford had us replacing the torque convertors. We often replaced torque convertors in the same trucks more than once. Then the torque convertor additives came out, they would fix the problem, without having to pull the transmission or convertor. Usually means the fluid is in need of changing.

[grishw1]

Probably a bad coil. I only buy what used to be Borg Warner coils for those things, Borg Warner is now Standard Ignition. They have lifetime warrantee, the Motorcraft coils do not, they all have the potential to fail. My 2002 F350, had it's first bad coil two weeks after I got it, I special ordered it, took possession of it the day it got to the dealer. Then a week or two after the first coil, I had another bad coil. Those two coils which are the rear two coils, I have replaced at least once each since. Kind of surprised at the coils being bad as early as they were, but it happened. They usually last a lot longer than that, but I found when I drive through water deep enough to splash up on the engine, it won't be long, before I have another bad coil or two.
The idea it's torque convertor shudder is a possibility, that does happen or we used to see it regularly. But for many years now, it's been pretty much a guaranteed thing, that when I have one that seems like a miss, it has a bad coil. I finally found a way of finding bad coils, too often there are not any miss fire codes, even though the engine has a miss most of the time, for some reason the computers regularly don't set a miss fire code. So I just pull all of the coils and inspect them, any I find that look suspect, I replace, so for 100% of the time, that has gotten rid of the miss the vehicle had.

There are other possible causes of a misfire. It could be lean. Lean misses are usually caused by vacuum leaks. The vacuum hose that goes to the PCV valve, usually has two rubber ends on it or a rubber elbow, that will get soft and gummy. When that happens, it will suck a hole in the hose. I would inspect the vacuum hoses first, make sure they are all good, the full length, any soft or gummy hoses, hard, brittle hoses replace. You could also have a EGR valve stuck open from being carboned up. Also the intake gaskets and plastic intakes are known to leak. Those will all cause a lean miss.
Good idea while looking for theses problems, to clean the throttlebody and IAC valve out very well, removing them and thoroughly cleaning them is best. Clean the throttle bores, front, back and the edges of the throttle plates, with carb cleaner. clean out the IAC valve also. Use some MAF cleaner or brake parts cleaner and clean the elements of the MAF sensor. Only use something that will dry fast and leave no residue. Be careful not to break the elements, only spray them off, definitely spray them down, if there is any gunk on either element. Those last things, will just make the truck run better, not fix a lean miss or a ignition miss.
On inspecting the coils, there is a blade up in the bottom of the coils, that looks like a male blade terminal. You need to remove the spring from the bottom of the coil, without damaging it. I pull and twist it gently, eventually it will come out of the bottom of the coil. Once you have the spring removed, inspect the blade up in the bottom of the coil. If there is any corrosion, green, gray, brown, replace the coil. What I have found happens, is water gets down in the spark plug hole and accumulates. Then when the engine is hot, that water turns to steam, which goes up, if there are any leaks in the bottom of the coil, the water gets up inside the coil. Once the water gets into the coil, it will cause corrosion, which you will eventually see on that blade on the bottom of the coil. I have found that is the only way to determine if a Ford mod motor coil is bad or not. Don't be surprised, if you have three or four coils with various color corrosion on the blades.
I have gotten many vehicles other people could not find the cause of a miss and had given up. Because they were looking for a miss fire code. First thing I check for large vacuum leaks, they pull all of the coils. I always find the cause of the misfire. There is one more thing that causes misfires with those particular engines, that is the spark plugs getting blown out of the head. Once it completely blows the plug from the head, it will break the coil and you will get a loud noise from that cylinder. My truck has blown two plugs out of the heads, both times, I got a intermittent miss, before it completely blew the plug out of the head. I had to put heili-coils in both heads. My truck has 269,000 miles on it. Many guys will tell you the heili-coils don't work or won't hold. I have had very good luck with them. I also have two different spark plug thread insert kits. The one that looks like the best design, is the only one, I have had blown out of the head, after installing them. Hope you don't have plugs coming out of the heads. Checking all of your spark plugs every once in a while is a good idea. They will be loose, before the completely blow out of the head. When you find one that is loose, like someone forgot to tighten the spark plug, it likely is about to blow the plug out of the head. I have found plugs that were loose, tightened them, then within a week the same plug blew out of the head. It was just a case of me finding the plug right before it completely blew out.

On the torque convertor shudder, if that turns out to be the case, you can buy additives to put in the fluid, that will usually cure the shudder. For years, Ford had us replacing the torque convertors. We often replaced torque convertors in the same trucks more than once. Then the torque convertor additives came out, they would fix the problem, without having to pull the transmission or convertor. Usually means the fluid is in need of changing.

WOW! Not my problem but I sure appreciate the response. Wish you were my neighbor!

[Mjjust]

I have a 2001 F150 with the 4.6 and 305,000. I’ve replace many a coil. One time I had something similar and couldn’t figure out what was going on. Finally took it to a mechanic I trust and he put a scope on it while running and it ended up being the coil boot. Coil was fine but the boot was bad and allowing a intermittent misfire. Just something to keep in mind.

[pervis]

Could be mass airflow sensor on it. Id replace it w a ford oem one. What your describing sounds like a bad coil. They fail alot on those trucks. I had a 03 150 v the v8. One thing to check is when your changing the bad coil. Make sure the old coil boot or part of it is not left on the plug. They dry rot and when you pull em off sometimes the rubber stays on your plug. When u put a new coil on it doesnt make contact like it should giving you a missfire. You can take a flashlight of a scope and shine it down in the cyclinder to make sure its clear. You ll be suprised at how much sand and bs builds up in those cyclinders on top of the plugs. You can take a long pick and scrape all the junk loose and vaccum it out. Hopefully that will help

[pervis]

As posted above, those trucks are notoriously bad for getting water down in the cylinders on top of the plugs. Like above that casues ypur coil to fail.

[.243 WSSM]

I suggest driving it on highway and see what it does at highway speed. My 03 has had problems lately and been through similar stuff. It still isn't back to 100% but much better. I had the same camshaft position sensor error you did. After replacing twice as well as bad 02 sensors it was good until it started lurching at highway speeds in overdrive cruising. It felt like the transmission was going out and only happened on the highway in overdrive. It has 298k miles and did flush at required intervals. After researching it sounded as if torque converter was going out. You could literally feel it on highway. Ended up being 2 coil over packs where the plastic on top had gotten brittle and the spark was arcing causing the engine to missfire only at highway speed in overdrive. After that the lurching was completely gone. It was very unnerving. Now I have a loose timing chain and not going to tear engine down for that. Hoping it holds together a few more months when I get my new truck

[Huntindad]

Probably a bad coil. I only buy what used to be Borg Warner coils for those things, Borg Warner is now Standard Ignition. They have lifetime warrantee, the Motorcraft coils do not, they all have the potential to fail. My 2002 F350, had it's first bad coil two weeks after I got it, I special ordered it, took possession of it the day it got to the dealer. Then a week or two after the first coil, I had another bad coil. Those two coils which are the rear two coils, I have replaced at least once each since. Kind of surprised at the coils being bad as early as they were, but it happened. They usually last a lot longer than that, but I found when I drive through water deep enough to splash up on the engine, it won't be long, before I have another bad coil or two.
The idea it's torque convertor shudder is a possibility, that does happen or we used to see it regularly. But for many years now, it's been pretty much a guaranteed thing, that when I have one that seems like a miss, it has a bad coil. I finally found a way of finding bad coils, too often there are not any miss fire codes, even though the engine has a miss most of the time, for some reason the computers regularly don't set a miss fire code. So I just pull all of the coils and inspect them, any I find that look suspect, I replace, so for 100% of the time, that has gotten rid of the miss the vehicle had.

There are other possible causes of a misfire. It could be lean. Lean misses are usually caused by vacuum leaks. The vacuum hose that goes to the PCV valve, usually has two rubber ends on it or a rubber elbow, that will get soft and gummy. When that happens, it will suck a hole in the hose. I would inspect the vacuum hoses first, make sure they are all good, the full length, any soft or gummy hoses, hard, brittle hoses replace. You could also have a EGR valve stuck open from being carboned up. Also the intake gaskets and plastic intakes are known to leak. Those will all cause a lean miss.
Good idea while looking for theses problems, to clean the throttlebody and IAC valve out very well, removing them and thoroughly cleaning them is best. Clean the throttle bores, front, back and the edges of the throttle plates, with carb cleaner. clean out the IAC valve also. Use some MAF cleaner or brake parts cleaner and clean the elements of the MAF sensor. Only use something that will dry fast and leave no residue. Be careful not to break the elements, only spray them off, definitely spray them down, if there is any gunk on either element. Those last things, will just make the truck run better, not fix a lean miss or a ignition miss.
On inspecting the coils, there is a blade up in the bottom of the coils, that looks like a male blade terminal. You need to remove the spring from the bottom of the coil, without damaging it. I pull and twist it gently, eventually it will come out of the bottom of the coil. Once you have the spring removed, inspect the blade up in the bottom of the coil. If there is any corrosion, green, gray, brown, replace the coil. What I have found happens, is water gets down in the spark plug hole and accumulates. Then when the engine is hot, that water turns to steam, which goes up, if there are any leaks in the bottom of the coil, the water gets up inside the coil. Once the water gets into the coil, it will cause corrosion, which you will eventually see on that blade on the bottom of the coil. I have found that is the only way to determine if a Ford mod motor coil is bad or not. Don't be surprised, if you have three or four coils with various color corrosion on the blades.
I have gotten many vehicles other people could not find the cause of a miss and had given up. Because they were looking for a miss fire code. First thing I check for large vacuum leaks, they pull all of the coils. I always find the cause of the misfire. There is one more thing that causes misfires with those particular engines, that is the spark plugs getting blown out of the head. Once it completely blows the plug from the head, it will break the coil and you will get a loud noise from that cylinder. My truck has blown two plugs out of the heads, both times, I got a intermittent miss, before it completely blew the plug out of the head. I had to put heili-coils in both heads. My truck has 269,000 miles on it. Many guys will tell you the heili-coils don't work or won't hold. I have had very good luck with them. I also have two different spark plug thread insert kits. The one that looks like the best design, is the only one, I have had blown out of the head, after installing them. Hope you don't have plugs coming out of the heads. Checking all of your spark plugs every once in a while is a good idea. They will be loose, before the completely blow out of the head. When you find one that is loose, like someone forgot to tighten the spark plug, it likely is about to blow the plug out of the head. I have found plugs that were loose, tightened them, then within a week the same plug blew out of the head. It was just a case of me finding the plug right before it completely blew out.

On the torque convertor shudder, if that turns out to be the case, you can buy additives to put in the fluid, that will usually cure the shudder. For years, Ford had us replacing the torque convertors. We often replaced torque convertors in the same trucks more than once. Then the torque convertor additives came out, they would fix the problem, without having to pull the transmission or convertor. Usually means the fluid is in need of changing.

heck of a reply. Thanx for all the info.
Geez...I hope a plug ain't ready to blow. My wife bought a coil after the first one I bought at autozone didn't seem to work. the one she got at O'reillys didn't even make contact with the plug. the spring just slid right over the plug, out the first one I bought back on and got the OEM CSS and it is running better, just not like it should.

thanx again

[Fordnandez]

These motors were also known for blowing the plug/stripping out the threads into the head. Usually it happens in the 5.4 supercharged lightning's or Harleys due to the cylinder pressure but it happened on my dads 00 4.6. The problem is so prevalent that there are kits to fix it.

Do a YouTube search for blown out spark plug.

[Slicefixer]

Probably a bad coil. I only buy what used to be Borg Warner coils for those things, Borg Warner is now Standard Ignition. They have lifetime warrantee, the Motorcraft coils do not, they all have the potential to fail. My 2002 F350, had it's first bad coil two weeks after I got it, I special ordered it, took possession of it the day it got to the dealer. Then a week or two after the first coil, I had another bad coil. Those two coils which are the rear two coils, I have replaced at least once each since. Kind of surprised at the coils being bad as early as they were, but it happened. They usually last a lot longer than that, but I found when I drive through water deep enough to splash up on the engine, it won't be long, before I have another bad coil or two.
The idea it's torque convertor shudder is a possibility, that does happen or we used to see it regularly. But for many years now, it's been pretty much a guaranteed thing, that when I have one that seems like a miss, it has a bad coil. I finally found a way of finding bad coils, too often there are not any miss fire codes, even though the engine has a miss most of the time, for some reason the computers regularly don't set a miss fire code. So I just pull all of the coils and inspect them, any I find that look suspect, I replace, so for 100% of the time, that has gotten rid of the miss the vehicle had.

There are other possible causes of a misfire. It could be lean. Lean misses are usually caused by vacuum leaks. The vacuum hose that goes to the PCV valve, usually has two rubber ends on it or a rubber elbow, that will get soft and gummy. When that happens, it will suck a hole in the hose. I would inspect the vacuum hoses first, make sure they are all good, the full length, any soft or gummy hoses, hard, brittle hoses replace. You could also have a EGR valve stuck open from being carboned up. Also the intake gaskets and plastic intakes are known to leak. Those will all cause a lean miss.
Good idea while looking for theses problems, to clean the throttlebody and IAC valve out very well, removing them and thoroughly cleaning them is best. Clean the throttle bores, front, back and the edges of the throttle plates, with carb cleaner. clean out the IAC valve also. Use some MAF cleaner or brake parts cleaner and clean the elements of the MAF sensor. Only use something that will dry fast and leave no residue. Be careful not to break the elements, only spray them off, definitely spray them down, if there is any gunk on either element. Those last things, will just make the truck run better, not fix a lean miss or a ignition miss.
On inspecting the coils, there is a blade up in the bottom of the coils, that looks like a male blade terminal. You need to remove the spring from the bottom of the coil, without damaging it. I pull and twist it gently, eventually it will come out of the bottom of the coil. Once you have the spring removed, inspect the blade up in the bottom of the coil. If there is any corrosion, green, gray, brown, replace the coil. What I have found happens, is water gets down in the spark plug hole and accumulates. Then when the engine is hot, that water turns to steam, which goes up, if there are any leaks in the bottom of the coil, the water gets up inside the coil. Once the water gets into the coil, it will cause corrosion, which you will eventually see on that blade on the bottom of the coil. I have found that is the only way to determine if a Ford mod motor coil is bad or not. Don't be surprised, if you have three or four coils with various color corrosion on the blades.
I have gotten many vehicles other people could not find the cause of a miss and had given up. Because they were looking for a miss fire code. First thing I check for large vacuum leaks, they pull all of the coils. I always find the cause of the misfire. There is one more thing that causes misfires with those particular engines, that is the spark plugs getting blown out of the head. Once it completely blows the plug from the head, it will break the coil and you will get a loud noise from that cylinder. My truck has blown two plugs out of the heads, both times, I got a intermittent miss, before it completely blew the plug out of the head. I had to put heili-coils in both heads. My truck has 269,000 miles on it. Many guys will tell you the heili-coils don't work or won't hold. I have had very good luck with them. I also have two different spark plug thread insert kits. The one that looks like the best design, is the only one, I have had blown out of the head, after installing them. Hope you don't have plugs coming out of the heads. Checking all of your spark plugs every once in a while is a good idea. They will be loose, before the completely blow out of the head. When you find one that is loose, like someone forgot to tighten the spark plug, it likely is about to blow the plug out of the head. I have found plugs that were loose, tightened them, then within a week the same plug blew out of the head. It was just a case of me finding the plug right before it completely blew out.

On the torque convertor shudder, if that turns out to be the case, you can buy additives to put in the fluid, that will usually cure the shudder. For years, Ford had us replacing the torque convertors. We often replaced torque convertors in the same trucks more than once. Then the torque convertor additives came out, they would fix the problem, without having to pull the transmission or convertor. Usually means the fluid is in need of changing.

Plugs blowing to Pluto, sounds like a 5.4 2v.....

I've got the 3v so no plugs blowing out, but, you might well break em all trying to get em out.....hehehe

Fantastic post....saved me a bunch of typing.....only caveats I'd add are the following....

- I'd only clean the MAF with MAF cleaner and be careful to avoid touching it beyond the end you remove it. It's evidently VERY sensitive.

- Ford makes a "friction modifier" that they recommend adding to the tranny fluid. I think that's what "RBP" is referring to in his post. Stops the "rumble strip"/misfire feeling and sound.

I'd bet it's plugs/coils. Be careful about trying to penny pinch in regards to both.
I wouldn't use ANYTHING but Motorcraft SP-546 plugs. These engines are VERY sensitive when it comes to the plugs and coils, but, more so the plugs.

Other than that he gave you some great, great advice ALL of which I've personally experienced....😉

[Shinesintx]

Don’t just replace one coil or boot. When one goes bad, replace them all. My last f150 was a 00. My current f150 is an 07. Combined mileage is almost 450k...it’s your coil and boots. Replace them all, especially if the current set has 60k on them...it’s time.