Let's find that lost cylinder 5 out of 6 ain't bad right

All 6 plugs show uniform rich condition. Can your scanner show diagnostic data, fuel trims, timing, coolant temp and so on?

Plugs below have 30k miles.

 

No my odb2 is a cheep princess auto job (Canadas harbour freight)

The plugs in this motor were changed by the previous owner.

They are ngk double ground. They are not that old but are BLACK with carbon deposits.

 

Thoughts on compression numbers ?

And DONT CHANGE THE COIL LEADS !!!!! Your 3.4L will not like it !

 

Yep, the significance being that your super rich burn looks equal across all 6. This would seem to indicate a system wide issue. You have the general miss fire code and the 3/6 cyl specific codes. Cyls 3 and 6 might be just a tad more susceptible to setting the code for other reasons like slight differences in spark or injector flow, not enough to be much of a problem on their own.

A scanner with diagnostic capability is nearly indispensable for this type of situation.

Compression looks good, good enough to not be the problem.

Gotta go.

 

One last thought for the nite.
That rich condition could be spawning the fires of hell and a melt down in your cat converter. Heck the converter could be plugged/restricted causing the problem in the first place.
Hard tellin, not knowin.

 

Rich and misfires generally mean bad injectors. Probably lots of carbon build up in there. They can't atomize the fuel well because the nozzles are clogged and the fuel comes out in droplets. Liquid fuel doesn't burn. So what happens is you get lean combustion in the cylinder and rich exhaust gasses as the un-combusted fuel is expelled.

This probably isn't the main cause of the 3-6 misfire though; that most likely the coil. When you have a misfire that is shared between two matched cylinders, its almost always the spark. Even though its sparking out of the cylinder, its probably not sparking strong enough in when operating inside the cylinder to ignite the air mixture; poorly atomized fuel isn't helping.

I would replace all coils and wires, spark plugs, fuel injectors, and your fuel filter. I would poor some seafoam into the engine when running to blow out all the carbon buildup and run some through your fuel tank as well.

 

Guess in Canada we don't get leakes in motors ....


nappppppaknowNOT . !

Called with the part # from video two different stores told me it was not their # ...... the search continues.

Also sea foam is going to happen !

 

Can you send a sample of oil to a company to be analyzed? They can generally tell, very accurately, if you have a head gasket leak.

 

I will look into this

 

Sea foam !

The one I need to clean injectors looks like you add to gas ! No spray bottle.

Problem is this truck is not on the road and putting it in the tank would take forever to run through the system and clean anything as it just goes up and down the street and idles while I play with it. Can I pour this into the intake ?

I know I know this is a long shot

But if I do this I might see a improvement and then it will give me better direction. Maybe

 

This one has a spray tube but lists it to clean intake and carbon deposits NOT INJECTORS,

Guess I will have to go over and read the can

 

And when the engine sees what it thinks is a lean condition it adds more fuel, adding to the fun. That can be seen with the proper diagnostic scanner (hint).

I have cleared a lean code caused by fouled injectors several times by running the engine on about a 50/50 mix of

$24 BG44K BG 44K Fuel System Cleaner Power Enhancer 11oz.

BG44K. Drain tank down to a gallon or so and add 4-5 cans. Run around the neighborhood in low gear, up and down RPM, mostly higher for as long as you dare and/or carry a gas can in case you run out. This replicates the best possible "in situ" pro cleaning process. Of course removal/cleaning/flow and pattern testing is better.

It doesn't take too many guesses with unneeded parts to surpass the price of a decent scanner or APP for phone/laptop.

You already swapped coils around hence the suggestion to swap the igniter.
Keep in mind the 2 plugs common to a coil are wired in series.

 

No amount of adding a cleaner to the intake air stream will do much for injectors.
I see you have limited "on road " ability. I siphon the tank down to near empty. It can be tricky to get a hose to the bottom of the tank.

 

Yes Rethinking this and it would not work for injectors !

So new plan

I am going to take the fuel filter OFF and have a look to see what kind of crap is inside it, this truck came from a small island of the coast of Newfoundland, as far east as you can go without getting wet !

Why am i telling you this ? Because i am sure the gas quality over there in Ma and Pa's small gas bar might not be the best !



While fuel filter is OFF i will fill filter with injector cleaner and reinstall. and dump the rest in the tank


If what came out of the filter is nasty then i might have to drop the tank to look inside ....

 

I will see if i can get one of my mechanic friends to pull the codes on one of their fancy odb2 machines.

 

$24 BG44K BG 44K Fuel System Cleaner Power Enhancer 11oz.

BG44K is VEVERY hard to find in Canada : (

 

Just change the filter, it's worth the $20

 

I hear ya on the small town gas. However even with good clean fuel be prepared to see at least a semi gray/brown metallic looking mess in the filter. The residue burnt off the fuel pump motor brushes collects in the main filter, the sparks are extinguished by the gasoline.

I would not be too concerned with a specific cleaner brand, it's more about technique and having a condition that a cleaner can actually help.

 

For seafoam, warm up engine to op temp, take a vacuum hose, preferably the one right behind the throttle body and poor it in there, carefully, while the motor idles. When your engine starts to diesel, just use your thumb to cap off the hose until your engine starts to idle clean. Once you get about 1/3rd of the bottle in the engine, shut it off and let it sit for abut an hour. Start it up and drive it or Rev it around 2-3k rpms until it stops smoking. It will smoke like a chimney fire. Repeat as necessary.

 

Let's do this !