Rear Bank Misfiring. 1 & 3 & 5 cylinders. Help is appreciated.

[wirebaugh]

Rear Bank Misfiring. 1 & 3 & 5 cylinders. Help is appreciated.
So my '97 avalon was misfiring and I had a #2 ignition coil crack and I replaced it. Ran great for a couple weeks and now this problem. All three rear cylinders (1&3&5) are misfiring. Fuel is being dumped, I can smell it. I can one at a time unplug all 3 rear fuel injectors and there is no change in the rough idle. Throwing 300,301,303,305 codes.

Got new wires, didn't help. Ran Seafoam, didn't help. Changed 02 sensor (needed to be changed) didn't help. Switched coil packs around, didn't help. Pulled the boots off the three rear plugs and I can hear the spark.

What would cause all three of that bank's cylinders not to work? Since I smell gas, the injectors are working. All 3 spark plugs wouldn't fail at the same time.

Could it be something vacuum or sensor related? If so, what controls all 3 cylinders? I've searched and can't find anything. Any help is appreciated.

[TedL]

Originally Posted by wirebaugh

Rear Bank Misfiring. 1 & 3 & 5 cylinders. Help is appreciated.
I can one at a time unplug all 3 rear fuel injectors and there is no change in the rough idle.

"No change" as outlined would indicate that all three cylinders are misfiring all the time, not occasionally. So your MIL would be flashing. Are you certain of this observation?

Any friend with a scan tool that will give you freeze frame and/or real time data? If not, it may be time to buy your own.

[wirebaugh]

Yeah it's not random. It's simply not firing on the rear bank. If it is sparking, which I think it is, it isn't lighting the fuel that I can smell.

I have a scanner. Haven't looked up how to do real time things though.

[TedL]

What's your coil setup? My 99 has three, on cyls 2-4-6. Same for yours?

Where are you smelling fuel? Out the exhaust?

Data could be very helpful.

[wirebaugh]

Yeah. Same coil setup.

Yes. Smell fuel out the rear of the engine.

I have the actron obd2 scanner from Autozone. I don't know if it is capable of realtime.
What data would you want if it is? If it's capable of doing it (I'll look it up right now) I'll run out and get the data right now.

[TedL]

Originally Posted by wirebaugh

Yes. Smell fuel out the rear of the engine.

Rear of engine???????????

Fuel trims and AFR/O2S data from freeze frame data would be the first thing I'd look at. If you really are just dumping unburned fuel, you don't want to be running it to get real time but burn out your cat.

Have you looked for vacuum leaks that would affect bank 1 more than bank 2?

Is there a chance that that spark plug wires are connected to wrong cylinders? Possible with aftermarket wire sets. Near impossible with OEM that come preassembled in the protective guide.

[wirebaugh]

DTC that caused freeze frame
P0300

Engine RPM
1204RPM

Load Value
33.7%

Coolant temp
82deg

Intake air temp
33deg

Short Term Fuel
Trim1 0.0%

Long Term Fuel
Trim 1 0.0%

Short Term Fuel
Trim2 0.0%

Long Term Fuel
Trim2 0.0%

Short Term Fuel
Trim3 -100.6%

Long Term Fuel
Trim3 -100.6%

Long Term Fuel
Trim4 -100.6%

Short Term Fuel
Trim4 -100.6%

Vehicle Speed 0 MPH

Fuel System 1
OPEN

Fuel System 2
OPEN

[wirebaugh]

Yes rear of engine, by the firewall. The bank 1 cylinders aren't firing.

Could you tell me what vacuum leaks would affect Bank 1?

I've tried both sets of wires, old wires and new wires, back and forth.
Wires should be set up like this right:

1 3 5
I I I
2 4 6
grill of car

And got a P1411 code too. (sorry forgot about that one)

[wirebaugh]

Anybody have a clue? I'm at a loss here.

Can anyone tell me what the timing should look like? I have a timing gun and read the timing, thinking maybe the timing is off due to the previous misfire/bad coil.

[BMR]

Originally Posted by wirebaugh

Yes rear of engine, by the firewall. The bank 1 cylinders aren't firing.

Could you tell me what vacuum leaks would affect Bank 1?

I've tried both sets of wires, old wires and new wires, back and forth.
Wires should be set up like this right:

1 3 5
I I I
2 4 6
grill of car

And got a P1411 code too. (sorry forgot about that one)

I think you've got the wires connected wrong. Should be:
1-4
3-6
5-2

Somebody please correct me if I've got that wrong.

[Brandoe91]

Did you figure it out? I have the same exact codes except the p1411 and can't seem to figure it out.

[Jason.MZW20]

Sometimes the ignition system kills the actual spark plugs. We're not sure why, but it has been observed on the wasted spark 1MZ. Try swapping in new spark plugs, or swap cylinder 2's with cylinder 1's.

-100% in each cylinder can mean the cylinder isn't firing at all. The ECU is trying to protect the cylinders from flooding with fuel and contaminating the oil. The only thing different from the front bank is the rear bank has an EGR pipe on the manifold. If that has cracked, the O2 sensor would read lean, not rich.

Otherwise, control grounds in the ECU for the fuel injectors are stuck on, and the O2 sensor is reading an extremely rich scenario and thus, removing fuel. This would require ECU replacement. You could try removing the two accessible fuel connectors (cylinder 1 and 5) and see if the fuel trim drops substantially. If it does, you're onto your issue.