22RE Cyl 4 misfire (w/video)

[the_dingman]

Hey everyone... I'm trying to diagnose a misfire on Cylinder 4 on my 4Runner. It seems to miss only at low idle, evening out once I give it some gas. I've replaced almost everything I can think of that could cause it...

- New plugs (NGK Platinum), gapped properly
- New wires
- New cap & rotor
- New Coil (Accel Super Stock)

Injectors were cleaned and balanced about 4 years ago by RC Engineering. It sounds as though all of them are firing fine when I used a stethoscope.

I did a compression test today, as well as when the injectors were cleaned a few years back (diagnosing a problem), and came up ~170 on all 4, with cyl 1 running ~160. I did another compression test today and came up with the following:

1: ~172
2: ~155
3: ~162
4: ~172

Attached is a video. It starts at high idle, where the miss is seemingly not there. It then drops to low idle, then I show the tailpipe, then back to the engine, removing one plug at a time. There is little to no difference on removing #4, with very large changes on every other cyl.

Ideas would be appreciated.

Youtube video

 

[Thurlo76]

maybe try changing out the plug. i know their new but that happened to me once and the "new" plug was cracked. maybe switch it out for a different one and see if it helps

 

[SV_Dude]

If anything, move the #4 spark plug to cyl #1 and see if the problem follows that plug. If it does then you know it's that plug for sure.

 

[the_dingman]

The problem was identical before and after changing the plugs, wires, cap, rotor and coil.

 

[SV_Dude]

If you had this problem before and after you changed basically everything on your ignition system then I would almost rule out the ignition system. I would do this:

Replace your PCV valve. A bad PCV valve could cause a misfire at an idle. Throwing a $3 part at it for curiosity isn't a big deal, I would do that just to eliminate that as a possibility.

Also, move your #4 fuel injector to another cylinder and see if the problem follows the injector. I know you said that you just had them serviced not too long ago but something could have gotten past your filter and is clogging up that injector.

One last thing: Maybe I'm just hearing things but I'm noticing a tapping sound from your motor that sounds like valve tapping. Check your valve lash. These 22re's are very finicky about little adjustments. If your lash is out then it could be giving that cylinder some trouble if the valves aren't opening and closing at the right time.

Good luck!

 

[the_dingman]

I didn't list them by mistake, but the PCV valve, PCV grommit, PCV hose and O2 sensor were just replaced as well, in addition to an entirely new exhaust from removing the cat on back.

The last thing I'm likely to try is moving the injectors (hopefully I'll find the problem). I had a hell of a time with them when I had them cleaned, and it took me 3 separate attempts of installing and removing everything to get the #1 injector to not leak at the rail.

I'm thinking the valves may be to blame. I did the timing chain, oil pump, water pump, etc about 2 years back with the help of a friend whom is an ASE certified Master Technician, and he adjusted my valves, but I think either the feelers were off, or we didn't let it warm up enough first.

I just need to find time to work on it.

 

[SV_Dude]

So basically you're saying that with the exception of the ignition system, everything on the motor is at least two years old? I wouldn't rule anything out based on two year old maintenance. Yes, these are reliable motors but things do break. Things do fall apart and wear out prematurely sometimes.

The best troubleshooting is the free troubleshooting. If you use the FSM, the injectors should be a breeze. Use a little bit of oil around the injector o-rings and there shouldn't be any reason that they wouldn't seal. If they don't, new o-rings are cheap. Do what you can that doesn't cost you anything first and definitely don't shy away from troubleshooting because parts of it may be difficult.

If you have a feeler gauge then you can easily check the valves on the #4 cylinder.