Need mechanical help

Hi, I have a 2011 toyota tacoma 4wd base with the 4.0 v6 and recently I pushed her a little and I suddenly have a misfire. Having serious misfires on cylinder 2 and 6 occasionally on cylinder 4, truck basically has cylinder 2 and 6 off until you drive it above 4.5k rpm then they all work. But replaced spark plugs, coils, injectors, cleaned the fuel system for no clogs, new fuel pump, new air filter, all my sensors working fine except for the 02 sensors. Bank 2 is showing me to be rich in fuel and bank 1 is lean. It shows the o2 bank 2 is stuck rich and bank 1 is stuck lean. I did compression test. Came at 180 for all cylinders, did fuel pressure test, came good, everything i replace the spark plugs, it runs slightly better for a couple minhtes and goes back to serious misfire and there is a bit of oil on the spark plugs when I take them out on bank 1. Reprogrammed the computer and don't know what else to do. It's been a pain to figure out what's wrong with my taco

 

Sounds thoroughly messed up, man! The compression test is encouraging at least, but the rest of this reads like a nightmare.

I would take a step back and check for spark and fuel at each cylinder. Maybe at least probe the wires that fire them, at each coil and injector. Maybe it's a wiring problem -- are there signs of rodent damage?

But you said you 'pushed her a little...' what do you mean by that? Did you, for example, push her into the ocean, or an active volcano? Check for saltwater in the oil pan, or lava in the radiator!

That was a joke, but I'd consider draining and examining the oil, and looking for signs of trouble in the coolant. Especially if, by 'pushed her a little' you mean 'overheated the engine' -- in which case, consider scoping or swabbing the cylinders for coolant, because you may have blown the head gasket, and that might not show up (yet) on a compression test alone.

If everything mechanical is good, then focus on wiring and the ECU. Or wait for someone more knowledgeable to reply.

In any case, welcome to TW, and good luck!

 

What brand coils did you buy?

 

Keep an eye on your oil for fuel satration. Sounds like you may have a injector imbalance. That would cause some to be lean trying to balance the other one(s). Could be a faulty coil or connection/connector. Could even be headgasket. Any oil in the coolant or "milkshake " in the oil? I'd diagnose the all above.

Remember the 3 basics to a running engine
Fuel
Spark
Mechanical

You have them all just 1 or more has issues.

 

there should be no oil on the plugs, wet plug wont spark. How many miles on truck.

 

You can also check
-for coolant ingress
-fuel pressures if not already checked
-borescope inside the cylinder and maybe pull valve covers to inspect head valvetrain
-gas quality
-leakdown
-maybe put new good O2 sensors

 

bad VCG leak would get oil on your plugs, cause a misfire
hope it's that simple. probably is

 

What exact CEL/ misfire codes are you getting?

 

worst thing is replacing parts one by one and with no improvement, this cost you lots of money. put it on a diagnostic machine and get it checked out. hopefully you can find the problem, and get to full recovery, good luck!!

 

Lots of parts thrown at the vehicle. If I suspect a faulty ignition coil I'm very hesitant to run right out and buy new ones, I'd be easter egging at that point because a misfire code on it's own doesn't warrant buying new coils. Swap it over to another location and see if the misfire moves with it. If so you have a bad coil, if it doesn't your coil probably doesn't need replaced. Same with a fuel pump, check the pressure if you suspect it's bad or think it's part of an larger problem. All that beats the hell out of buying a new one to find out symptoms didn't change. If we brought it to a dealer and all those parts were replaced you'd be saying WTF, how did all these parts go bad at once? Obviously they didn't. Not trying to knock the OP, it's frustrating having issues and not finding the problem. My point is try and get some corroborating evidence before throwing parts at a problem.

 

I bought duralast gold coils and it worked exactly the same, switched them out too and the same 2 cylinders misfire

 

Only about 105k

 

For meaningful help, please elaborate on your opening statement -- that you 'pushed her a little.' This means that something happened, and that you think this might have caused your problem.

Does that mean you were once 500 miles late on an oil change because you were working two jobs just to make ends meet? Perhaps you briefly overloaded the bed when you got a fantastic deal on firewood to heat your house this winter?

Or, does that mean you blew the radiator during a police chase, overheated the engine, and warped the heads beyond repair... then murdered a convenience-store clerk over a carton of eggs to patch the leak, refilled it with swamp water, then limped her 2100 miles to your crazy uncle's ranch in Wyoming, with the oil light flickering ever since Missouri? (Distance estimated based on my assumption that this must have begun somewhere in Florida.)

In any case: Blindly swapping engine components with gutter-quality replacement parts based on generic ECU codes was a poor plan in the first place, and is now even less likely to resolve the problem.

Over half a dozen additional people have stepped up to help you here, likely all of whom know more about these trucks than I do. But none of us can provide meaningful help unless you are more forthcoming and responsive on the forum.

I have owned and maintained over a dozen other cars of various makes and models -- nothing quite compares to the Tacoma community. These people can and will help you, but only if you provide the full story, and follow through on collective diagnostic recommendations.

 

Easy there mk5.

I think in fewer words hes trying to say...
More exacts will help lessen or even eliminate the parts cannon.

Good input = good output

 

I'd be thinking valve stem seal if it was a chevy, but you'd get some blue smoke on start up.

 

Thank you, I slightly toned-down my reply. I am eagerly standing by to provide further assistance to OP; although the scope of this repair will likely eventually exceed that of my knowledge, we are presently limited by what little information has yet been posted.

Despite perhaps failing to illustrate this by example, my point was that TW is an overwhelmingly welcoming and helpful community. I commend @1 Limited Toyota for holding me to a higher standard, and hope that the modified reply above compels further details from OP without being offensive, while still being entertaining to read.

 

Btw after rereading, to the op's credit it gives a fairly decent discription of what it is doing wrong (issues).

The part about pushing it was vague and could help the puzzle but really doesnt effect the repair reality.

No mention of codes. Any?

 

Ha ha we all do it. I gotta bite my tongue regularly.