Running rough v6

[ALAG3]

My muffler was rusted out and a friend of mine had a used muffler from another vehicle that we put on my "new to me" 4runner. Ran fine on the way home. At home, I replaced the air filter and now it is running rough, especially when accelerating under load. Problem seems to get worse and better, sometimes sputtering out the exhaust. Not sure if the muffler is connected to problem because it ran fine on the way home. Prior to me buying it, the vehicle sat for about a year, so I suspect maybe water in the fuel tank? I have run a complete tank of fuel through it and this problem began also when the fuel level was low. I refilled the tank, but no change. Any suggestions on where I should start?
I looked for cracks in the intake hose that maybe were caused when i pushed the lid of the airbox up to replace the filter, but found none.
Thanks for any input!

 

[GonOvr]

Check the connection at the VAF (top of the air filter housing), you may have knocked something loose when you put the filter in.

Could be fuel related, probably should start by replacing the fuel filter since it sat for a year.

Run some seafoam through the gas tank, and intake. Might have some gunk stuck in it.

 

[KidVermicious]

I don't know the v6 so I'm shooting in the dark, but if the poor performance is related to your muffler work, I'd suspect an O2 sensor.

But you say it started when the gas was old and low - that sounds like sediment. Try changing your fuel filter yet?

 

[90 t4r]

i will say this my 4runner sat for a considerable amount of time longer than yours ~3 years before i bought it and when i finished my rebuild i ran into the same problem changed the fuel filter to no avail checked everything else and narrowed it down to a fuel problem, so i pulled the upper intake plenum back off and snapped out my fuel injectors and 2 of them were slam packed with rust and sediment so i cleaned them and thought i was done with it, but like an idiot i ran low on gas again and it started acting up again changed the fuel filter no help so again with the injectors but this time i also dropped the fuel tank and low and behold at the crap that was in there omg looked like some one took a funnel and poured dirt down the filler neck, not to mention the rust on the walls of the tank, so needless to say a little over an hour later with the shop vac and a wire brush i got as much out as i could changed the fuel pump strainer and put it together and as of yet i have had no other problems, just wat it was in my situation

 

[ALAG3]

I am going to run some seafoam through this afternoon, but I am also thinking about the injectors. Are they a big deal to remove and clean?

 

[GonOvr]

I am going to run some seafoam through this afternoon, but I am also thinking about the injectors. Are they a big deal to remove and clean?

Injectors need to be cleaned internally. By pulling the injectors, you could clean the exterior and tip but that's it. As said before just run a good quality fuel cleaner in the tank. You could also take it almost anywhere and get an injector service done.

 

[ALAG3]

Well, I figured that out after pulling the air intake off. I put it all back together and I have bigger problems! Sounded like something loose inside the cylinder when I started it. I pulled the plug on the driver's side near the firewall and saw something in there. Inserted a magnet and found what looks like a HALF of a washer. It must have fallen down into the intake. Now the problem is where is the other half! (What a stark reminder that I am not a mechanic!) I pulled the valve cover off and do not see it there either. :shrug: Out of frustration, I finally gave up for the night. Maybe a fresh mind tomorrow will produce better results. (BTW, yes, I am an idiot!)

 

[GonOvr]

Well, I figured that out after pulling the air intake off. I put it all back together and I have bigger problems! Sounded like something loose inside the cylinder when I started it. I pulled the plug on the driver's side near the firewall and saw something in there. Inserted a magnet and found what looks like a HALF of a washer. It must have fallen down into the intake. Now the problem is where is the other half! (What a stark reminder that I am not a mechanic!) I pulled the valve cover off and do not see it there either. :shrug: Out of frustration, I finally gave up for the night. Maybe a fresh mind tomorrow will produce better results. (BTW, yes, I am an idiot!)

Well if I understand you correctly. You pulled a spark plug out and retrieved part of a washer. If this is the case, more than likely the head, cylinder and piston are trashed. You may have dropped something down the intake and it made it to the cylinder. This means at the least it is time for a rebuild at least. More than likely a new engine though. The other half to your washer is probably imbedded in the cylinder somewhere.

 

[ALAG3]

GonOvr, you were right on the money with the engine being trashed. Pulled the motor and tore down the motor. The other half of the washer was embedded in the head, the piston was trashed. Fortunately the cylinder wall was not scored. Probably was a blessing in disguise though, as I found a handful of other problems during the teardown that were not related to the washer.
The injectors were packed with tiny particles of rust, so a new tank, fuel pump and sending unit are on the way. After flushing the fuel lines and replacing the injectors, the engine is about 90% reassembled with a new piston, and all new gaskets. I am hoping we can get it dropped back into the Runner on Saturday morning and hear it run again. I sure hope this investment doesn't continue to be a money pit!

 

[77'911]

Could be any number of things:
-water in the petrol from sitting
-differing back pressures from new/used muffler
-used muffler is clogged with rust
You might consider changing out the fuel filter and running a bottle of techron concentrate through it.
regards

 

[mikedks]

Could be any number of things:
-water in the petrol from sitting
-differing back pressures from new/used muffler
-used muffler is clogged with rust
You might consider changing out the fuel filter and running a bottle of techron concentrate through it.
regards

Or...If I read the thread correctly, ahem...a washer that fell into the engine
and trashed the cylinder and head. he he he he he