Help! cylinder 3 misfire
 

Hey guys. I am hoping someone can help me out. I have a 2001 supercrew 4x4 with the 5.4L engine. While driving home yesterday the truck stated shaking pretty violently and then the CEL came on. I checked the code and got a misfire in cylinder 3. No big deal. Had the same problem a while back on #6. So today I picked up a new cop and a motorcraft spark plug and installed them on cylinder 3. It didn't fix it. And now I got a new code. P0171-system too lean (bank 1). Since I know cylinder 3 is getting spark now could the fuel injector be clogged or just not working properly? Would a clogged fuel injector throw a misfire code? Any help would be greatly appreciated. I hate to buy an injector just to find out that wasn't the problem.

Thanks!

Is the missfire 'still' on cylinder three 'by code'?
Next do you have the right cylinder?
#3 is the third one back from the front on the passenger side.
Don't buy parts in hopes of getting lucky.
Find the cause, then the part to fix it.
The only time for a sudden drop of a cylinder would be no spark or no fuel barring a cam lobe or valve failure.
Be sure the new coil is good and your working on the right cylinder and the boot is down on the plug and not jambed up to the side.
Good luck.

Yes the trouble code still says the misfire is cylinder 3. When I replaced the cop for #6 I printed off a picture of the cylinders with their numbers on it and kept in the glove box for tracking which ones had been replaced and so I always know which cylinder is which. I did replace the cop and spark plug on the 3rd one back on the passenger side. I also thought I might not have the boot on there correctly so I took it off again and checked. I could tell the spark plug had been in the boot because you could see the dielectric grease had been pushed up into the boot. Is there any way I can check the injector to see if it's getting fuel through it?

If the injector is plugged or open you would have to remove the fuel rail for that side.
Maybe you would consider swapping two injector positoins to see if the missfire follows with a code for that cylinder.
Good luck.

How did the spark plug look?

Did the p0303 come back or just the p0171?

Thanks bluegrass. I will try to swap two injectors and see if that changes things.

Neo, The spark plug I took out didn't look that bad I didn't think. It had some carbon on it but didn't seem to me to be burnt up or anything.

Toyz, the p0303 was the original code and was the only code in the beginning. The p0171 didn't show up until after I put a new plug and cop on. But yes the p00303 is back also.

Thanks everyone for your help. I really don't know where to go from here other than to take it somewhere but I don't know anyone around here I can trust to give me an honest estimate. I will try to swap two injectors and see what that does and let you know what happens.

You really have to watch the dielectric @ the spring/plug contact point. Meaning "0" grease should be involved with these particular mating surfaces. Simply because there's not enough force pressure to squeeze the grease out adequately for clear and positive contact.

Dielectric = A nonconductor of direct electric current. Trust me, you definitely want complete/maximum pulse contact @ the plug/boot spring connection working with COP ig systems.
They are not same in comparison to plug wire and plug connection. The rules change because of the connector/conductor force. Plug wires have a much stronger force, strong enough to clear grease from contact points once connected, so contaminating the connection isn't really a big deal. You don't have that luxury w/Coil On Plug systems. The only exception would be to run Solid Connectors. AFAIK Granitelli is the only provider of such connectors for these model Fords.

You know what I mean?

There needs to be a certain minimum contact-to-contact force to clear the non-conductive grease. COP systems lack this force @ conductor connections , (-spring plug connect).

So make sure you always clear ALL grease from spring end before mounting a COP system coil onto the spark-plug. Or you may be yanking the rest of your hair out attempting to figure out why the engine is misfiring.

BTW- Easy way to do this is to just grease the snot out of the boot, then shove the coil spring thru. -With a screwdriver or hemostats (works best), pull the spring from boot end approx 1/2". Swab the spring end contact point with Acetone or Lacquer thinner. Let the spring go and it will recoil back into the boot. The coil is now ready to mount.

D-grease is great stuff when used/applied properly. If not, there can be headaches. :thumbsup:

Hey Jbrew. I did not know that about the grease. So where exactly is it supposed to be applied? The outside of the boot? Or the inside of the boot but not inside the spring itself?

Put it inside the boot, but keep it off the tip of the spring that contacts the plug.If unsure, pull it out and clean it as jbrew suggested, and you should be good to go.

I finally got around to working on my truck today. I found that #3 cylinder has no compression. Doesn't even move the needle on the gauge. Any ideas? I'm leaning towards broken valve spring. The motor doesn't make any noise and doesn't smoke. At least I'm hoping it's a valve and not a piston with a hole in it.

The least you can do is remove the valve cover and look at that cylinders valve train.
If you see it normal, rotate the cylinder to it's compression stroke as evidenced by both valves being closed at the same time.
Try air pressure into the plug hole and listen to the intake and tail pipe for the sounds of air rushing as well as in the crank case.
It would show a valve not sealing or a piston not sealing etc.
Good luck.

Thanks Bluegrass, I'll try that when I have time. I'm not looking forward to taking the valve cover off. Looks like a lot of stuff in the way that has to come off first. Is the 2 valve engine an overhead cam engine? If the valve spring is broke I'm guessing the cam will have to come out to fix it?

the cam does need to come off.. Still that would be your best case. Get the valve cover off and see whats going on. Good chance your gonna need to pull the motor. Thats a way bigger deal then fixing a broken valve spring.

Hey Jet, I'm curious as to why the engine would have to be pulled if the problem was a valve or a valve spring. Looks like there are rebuilt heads available for less than $500. It's not possible to replace the head with the engine still in the truck?

He didn't mean it in the case of replacing a valve spring as he said that would be the least of your worries. Maybe it broke a valve and went through the piston, who knows yet..? Your worst case would be pulling the motor for an overhaul. And yes, you can replace a head with the engine in the truck.

Ok. I understand. I'm not sure what's going on yet but I'm hoping the piston isn't ruined. If the piston had a hole knocked in it would it smoke or at least the spark plug be oily?

How many miles are on that engine? if its not a broken spring you really at that point need to start asking yourself if its worth trying to contine to patch up a 16 year old engine with x amount of miles.. pulling the heads is only a little less intensive as pulling the engine.. 16 year old engine.

Hey Jet. I have 188,000 miles on the truck. I have a receipt that came with the truck from the dealer who sold it new that the engine was replaced at 60,000 miles. The original owner took it in for warranty work and said the engine was ticking and the technician said it was knocking so they replaced it. I don't know if the original heads were used or if they were new also. So the engine has about 128,000 miles on it. The truck has been very good to me and still looks great. Everything works like it's supposed to. This is the only real issue I've had with it.

Now I'm thinking about finding a complete engine from a salvage yard with less miles on it and just yank out the old and drop the working engine in there. Does it have to be the same year? Can I put a newer 3 valve engine in there? Also, when I swap them is it a plug and play deal? Will the pcm know it's a different engine and keep it from running?

You can't use a 3 valve because the PCM program is completley different in version and valve train control along with the hardware and harness.
Good luck.

Ok, that settles that. Do you happen to know what years I can use? And will I have to get the dealer to reprogram anything to get it to run?

1st part: should be able to use 99-03. you may or may not have to swap some accessories over from your current engine to the replacement

2nd part. You shouldnt need to have the dealer do anything. Its just a bunch of bolts to swap engines :rolleyes: :roflol:

Did you ever figure out if you have a broken spring/valve, etc. on cyl. 3? I would hold off on doing anything until you figure out what happened to the current one so you have a cost to repair vs engine replacement figures and time factors

Thanks for the reply. That's the answer I was hoping for. I haven't taken the valve cover off yet to look. I'm hoping to get a chance to look at it this weekend. I don't know much about these engines. Frankly the whole overhead cam scares me as far as getting it timed right if you have to remove the cam/head to repair a valve or spring. I miss the small block Chevy days with the old push rod engines. That was something I could work on.

.....

Me and my buddy are gonna try to get the valve cover off tomorrow and see if we can figure out what happened. It sucks just seeing my truck sit in the driveway.

Ok guys I need some advice. I took the valve cover off and couldn't see anything wrong with the cam, rocker, or valve spring. So I made sure both valves for #3 were in the closed position and hooked some air pressure up to the spark plug hole. The air just rushed out of the pcv hose that was now hanging from the intake. If I put my finger over that it sounded like it then came out the air filter. I'm guessing the intake valve is shot. I'm not going to attempt to pull the head off with the engine in the truck. I will pull it all and take the head off to see what is wrong. My question is, if the pistons and everything look good in the bottom end do I just replace the head or since I have it out should I go through the whole motor or buy a re-manufactured motor. I am trying to build a house so money is an issue but I don't want to do this again in the near future.
Thanks for any advice/opinions.

If anyone is still reading this thread I got the head off today. What a pain in the a$$! I'm not sure how I'm going to get it back on. The bolts on the back of the RH head that hold the metal coolant line that runs under the intake from the back of the water pump were almost impossible. Anyway I found that the block is in excellent shape. You can still see the hone marks on the cylinder walls. The problem is the intake valve on #3 never closes. After we got it off, we rotated the cam and watched all the valves open and close but that one never seals up. I cant tell what is holding it open. There is about 1/8 inch of daylight all the way around it when it should be closed. I will have the head rebuilt or replaced. Does anyone know where a guy can get a good quality rebuilt head or where to send it out to have it repaired? Also, there is a wire in the valley that hooks to something bolted into the block. Anyone know what that is? It looks like it has been leaking oil. I would GREATLY appreciate anybody's help, suggestions. I'm kind of in uncharted waters here for me.

Ya these motors are complex to work on so you need to be sure you know how to put the timing chain on correctly when the time comes.
The wire goes to a sensor in the valley area.
There is no oil in that area but oil can leak down from above and lay their.
Inspect the coolant line or replace it..
With the cam off the head; if the valve is stuck open very carefully see if carbon or some material is holding it open or the lifter assembly has some- thing wrong.
If you find something was holding it off seat and nothing else is seen to be a problem the head may be able to be put back on as is but do find out what the original issue is first before makeing that judgement.
If not, the valve stem is frozen in it's guide for some reason. If a tap with a hammer seats the valve then the guide area is the problem.
This is a rare occurance for an intake valve to stick like that.
Usually an exhaust valve will be more prone to stick from heat.
Note in my first reply #2 that I mentioned a possible valve issue right away.
The way to tell this was to bring that cylinder up on compression stroke then apply air through the plug hole and see where the air was escaping.
You would have heard it in the intake through the throttle body.
Good luck.

Now that your there if it were me I'd go ahead and pull the other head and take them to a machine shop and have them reconditioned.. Head gaskets on both sides. Reconditioning head isnt that much You should be able to do both for around 400. and pulling the engine isnt much harder then taking the heads off but you are that far so finishing it is good.. Sounds like that would fix it and really your engine isnt that high miles. Get some good literature to help.

Hey guys, thanks for the replies! I was afraid you all had given up on me.

Bluegrass, I took your advice and pumped some air in that cylinder and it just rushed out of the intake manifold through the pcv hose. That's when I knew the head had to come off. I really appreciate all of your help and knowledge for those of us who are not so well versed on these engines. The coolant line looks fine but I am going to replace the two O rings that seal it up to the water pump. It doesn't look like it has ever leaked coolant in that area. I printed the write up on how to get the timing chains back on correctly. It sounds easy enough and I can still clearly see the white marks on the chains. One end has one link marked and the other has two links marked.

Jet, I'm going to take the head to a shop tomorrow and see what he can do for me. I would like to have the peace of mind that it is fixed correctly after all this.

I have another question about the injectors. What is the best way to store them while they are out of the fuel rail so the o rings don't dry up? Should I put anything on them like wd 40 or light oil?

Thanks guys. I don't know what I'd do without help

Dont worry about the injectors theyll be fine. Just lube the oring a bit before you install them

The repair manual I have shows that the metal coolant line running from the back of the water pump to the heater core has a piece of rubber hose connecting it to the water pump. Mine is all metal with 2 o rings to seal it up. Does anyone know it the rubber "splice" is a good way to go? That sure would make putting the head back on easier. I could have the tube already bolted to the back of the head and not have to try to get between the head and the firewall on reassembly.

Ok guys. I have the rebuilt head back on and the truck is almost ready to be cranked over. Since I had the head off and the timing chains/gears off should I crank it without the fuel pump fuse so it can pump some oil before the thing fires up? I ruined the harmonic balancer because I'm an idiot so that's my hold up right now. It should be here tomorrow morning and then it just needs the radiator and antifreeze. I just don't want to screw something up because of lack of lubrication.