Misfire all Cylinders

[camino70]

I replaced my 10+ year old Michelins with 4/32 last week with K02, I was getting excited I haven't seen the Misfires CEL's since.
Then today, pending P0101 "Mass Airflow (MAF) Circuit Operating Range or Performance Problem" and P2198 "02 Sensor Signal Biased/Stuck Rich Bank 2 Sensor 1"

 

[Cruisin911]

I'm still saying MAF. Go get one from toyota parts desk. If it doesn't work, take it back. Nothing lost.

Also, what's your mileage? If over 100k, its a great time to change all our 02 sensors as their typical life is around 100k.

 

[camino70]

I'm still saying MAF. Go get one from toyota parts desk. If it doesn't work, take it back. Nothing lost.

Also, what's your mileage? If over 100k, its a great time to change all our 02 sensors as their typical life is around 100k.

Not a bad idea. I bought denso and Hitachi (not toshiba), but not from Toyota.
I’m at 200k. I swapped my original maf and bank 2 sensor 1 back in tonight to see what happens.

 

[camino70]

I found some additional information on troubleshooting.
Step 1, address codes that are not P0300-P0308
Step 2, get misfire rpm and load - looks like I am getting my OLD laptop out
Step 3, check PCV (thanks @TheGrrrrr - I will triple check - hopefully I messed it up. P0101 lists PCV has a potential culprit too)
Step 4, check catalyst in techstream
Step 5, active test
Step 6, check plugs
Step 7, check spark
Step 8, check compression
....... Step ?
We'll see how far I get Saturday morning....

 

[Cruisin911]

Not a bad idea. I bought denso and Hitachi (not toshiba), but not from Toyota.
I’m at 200k. I swapped my original maf and bank 2 sensor 1 back in tonight to see what happens.

My main reason for pushing those two items is that they're both single point failures that can cause your observables. It is highly unlikely that something went wrong on all 8 cylinders and much more likely that a common point of failure that feeds those cylinders is operating incorrectly, i.e. the MAF or O2 sensors.

Best of luck. Hopefully its a simple fix.

 

[grinchy]

Could the crankshaft position sensor be involved? it isn’t expensive . . .
That is if you’re throwing parts at it

 

[camino70]

Could the crankshaft position sensor be involved? it isn’t expensive . . .
That is if you’re throwing parts at it

I am throwing parts at it. I did the crank sensor too.
I pulled the Pcv to make sure I didn’t break it. I don’t see any obvious problems. It allows pressure out, but not vacuum in.
My oil cap seal looks beat, could that allow anything by it and cause an issue? @CharlieS - thank you

 

[bronc076]

How thoroughly have you checked for a vacuum leak? I'm wondering if there is an issue with the intake, cracked plastic or bad gasket. I use carb cleaner to look for vacuum leaks, but a propane torch (not lit of course) might be a good method too. move it around the intake and air hoses while the engine is idling, idle should increase when you find the vacuum leak. First I'd do a very thorough visual inspection of all the plastic between the MAF and the heads.

 

[camino70]

How thoroughly have you checked for a vacuum leak? I'm wondering if there is an issue with the intake, cracked plastic or bad gasket. I use carb cleaner to look for vacuum leaks, but a propane torch (not lit of course) might be a good method too. move it around the intake and air hoses while the engine is idling, idle should increase when you find the vacuum leak. First I'd do a very thorough visual inspection of all the plastic between the MAF and the heads.

I can't claim to be proficient at it, but have spent quite a bit of time spraying soap/water and visually inspecting.

 

[CharlieS]

My oil cap seal looks beat, could that allow anything by it and cause an issue? @CharlieS - thank you

It creates a vacuum leak. I can't speak for how it impacts the land cruiser, but it caused issues on a 911.

 

[camino70]

1 no other codes at the moment...
2 misfire rpm 1200, load 0.84

Misfire rpm load

• camino70
• Mar 13, 2021

looks like cyl 4 and 8 and misfiring right now.

3 pcv looks ok, I’ll be getting some propane to test for leaks later today.

4 I don't see catalyst OT MF F/C in techstream, should I? The alternative directs to Misfire count.

 

[bronc076]

carb cleaner or starting fluid work well too. I've re-read this thread. Do I understand correctly, this problem only occurs when the engine is cold, everything is fine once it warms up?

 

[camino70]

I would normally use carb cleaner, not sure why not now. I don’t have any, so a trip to the store is required anyhow.

misfire count appears to roll over, only 4 and 8 are showing now. There numbers are consistent with one another.

#4, but doesn’t look all that different from #1 and 2.

4 plug

• camino70
• Mar 13, 2021

 

[gaijin]

I would normally use carb cleaner, not sure why not now. I don’t have any, so a trip to the store is required anyhow.

misfire count appears to roll over, only 4 and 8 are showing now. There numbers are consistent with one another.

#4, but doesn’t look all that different from #1 and 2.

4 plug

• camino70
• Mar 13, 2021

That doesn't look like the specified Denso Iridium plug, is it?

 

[camino70]

You’re right. I ordered denso and auto lite app5325. The autolites got here on time, first.

 

[camino70]

All plugs (autolite app5325) are gapped at .041 without adjusting the gap.
All tested and show spark.
All cylinders are between 170 and 175 compression.
All plugs retorqued to 15 lbs.

No codes, but there were a few individual misfires on start up, 9 all cylinders. It did NOT trigger misfire rpm or load though. This is restarting, not initial cold start.

Restart no misfire.jpeg

• camino70
• Mar 13, 2021

 

[camino70]

Any advice on how to run active test Prohibit the Catalyst OT Misfire prevent F/C? I see it in techstream and can turn it off/on, but I was expecting it to prompt me with steps.

 

[gaijin]

You’re right. I ordered denso and auto lite app5325. The autolites got here on time, first.

All plugs (autolite app5325) are gapped at .041 without adjusting the gap.
All tested and show spark.
All cylinders are between 170 and 175 compression.
All plugs retorqued to 15 lbs.

No codes, but there were a few individual misfires on start up, 9 all cylinders. It did NOT trigger misfire rpm or load though. This is restarting, not initial cold start.

Restart no misfire.jpeg

• camino70
• Mar 13, 2021

Not saying it's a cause of your problems, but seems that using those Autolite Platinum plugs with a different gap than specified in the Owner's Manual might be a variable that could be a problem. Here's what the manual says:

Just sayin'

HTH

 

[camino70]

Thanks gaijin, I will find my densos 3421, measure them and try them. I am showing them online to be .044, not .043 as your screenshot indicates.

The document I am working from says 1.0mm - 1.1mm; .0394 - .0433:

checkplug.jpg

• camino70
• Mar 13, 2021

 

[camino70]

carb cleaner or starting fluid work well too. I've re-read this thread. Do I understand correctly, this problem only occurs when the engine is cold, everything is fine once it warms up?

Correct.