Misfire all Cylinders

[gaijin]

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

The Denso website (See it here: 3421 SK20HR11 Product Specifications) shows the

3421 SK20HR11 Iridium Long Life Spark Plug​

Gap = .043" (1.1mm)

Which is consistent with the Owner's Manual.

HTH

 

[Mtntopper]

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.

Pretty sure electrical parts are non-returnable after plugging in.

 

[04UZJ100]

We have misfires on all cylinders and are running “auto lite” spark plugs? Use OEM and report back.

 

[camino70]

Thanks guys, this problem started with Toyota plugs, maf, pcv, crankshaft position sensor. They were all overdue, so I went ahead with replacing them. I will swap in the denso's plugs I have today. Aside from cold start up, the truck runs fine.

I continue to keep an eye out for any compromised wiring or remnants of a critter, but I haven't found any yet, any particular places I should look harder?

I could still use guidance 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.

 

[TeCKis300]

Check your coolant temp sensor. Check it physically but also see what it's reporting in techstream.

If your problem now lies in cold start, the coolant temp sensor acts like a choke in modern cars. If it's not working or reporting the right temperature, the ECU will have trouble providing the correct enriched mixture, or an overly enriched mixture, that could lead to misfire.

Sorry, don't have any insight into Prohibit the Catalyst OT Misfire prevent F/C.

 

[camino70]

The denso 3421 are at most .041.

some plugs, left autolite with a couple hundred miles, pulled immediately after stumbling misfire. Middle put back in run several miles without stumbling and pulled, right denso. Bottom autolite with several miles no stumbling.

Plugs.jpeg

• camino70
• Mar 14, 2021

Autolite.jpeg

• camino70
• Mar 14, 2021

installed the denso 3421 after letting it sit and cool a bit. Misfire and pending dtc on all cylinders at initial startup.

Post denso misfire

• camino70
• Mar 14, 2021

 

[camino70]

Check your coolant temp sensor. Check it physically but also see what it's reporting in techstream.

If your problem now lies in cold start, the coolant temp sensor acts like a choke in modern cars. If it's not working or reporting the right temperature, the ECU will have trouble providing the correct enriched mixture, or an overly enriched mixture, that could lead to misfire.

Sorry, don't have any insight into Prohibit the Catalyst OT Misfire prevent F/C.

Thanks, any guidance on proper ranges?
I let it sit for a bit this evening, but it didn’t cool down much. Initial start up coolant temp 158, air temp 150. After idling a few, 172 and 117. No misfires.

 

[TeCKis300]

Is 158F cold start or is the coolant already warmed up and this is a warm start? I'm assuming warm start as air temp is 150F also?

Does your problem lie in cold, warm, or hot start?

Coolant temp at cold start should show pretty close to ambient temp.

 

[camino70]

It’s warm start, I was hoping it cooled more and wanted to get eyes on temp in tech stream. Cel is from cold start

 

[camino70]

This morning temps showing 68 and 52. About 15-30 seconds in, CEL and stumble came out. My techstream is acting up and crashing frequently, I cleared codes. I was able to reproduce three times in a row, but haven't had a chance to really look/see anything in techstream.

Edit: Trying to keep an eye on misfires at startup, it looks like all cylinders show misfire and total count goes to 255 quickly.

Edit 2: A neighbor with a 5.7 Tundra may let me swap MAF to see if my problem follows the sensor or stays with the truck. Looking online, they appear to be the same part number, does anyone have knowledge if I will be causing a problem, especially for him?

 

[nwfl4runner]

MAF should be fine to swap. Have you checked continuity to the crank position sensor?

 

[camino70]

MAF should be fine to swap. Have you checked continuity to the crank position sensor?

Thanks. I put my MAF in his truck and it didn't seem to care. Tundra cold started and idled fine, no CEL, no stumble.

Put the tundra MAF in LC without issue, but it's warm at this point. I left the hood up to cool and unhooked the battery, I'll try again later.

I have not checked continuity on the crank position sensor, I need to look that up.

 

[bronc076]

edit double post

 

[bronc076]

I'm still thinking it a big vacuum leak like a crack in the plastic intake manifold or bad gasket or something that is drastically affecting mixture in open loop cold start scenario. But most of my fuel injection knowledge relates to older systems, and I'm not sure how idle air is handled on these engines. Since it is fly by wire throttle does the main throttle plate handle idle air or is there a separate Idle air control like on an engine with a mechanically operated throttle plate? Aside from ECT which what other sensors are monitored to alter scenario from open loop to closed loop operation?

 

[camino70]

I used to be able to hear vacuum leaks, but I can't seem to find/hear anything of the sort. I found my propane bottle, but now I can't find the nozzle. I'll try to pick one up this week and give it a go.

I tried testing the crank position sensor, there is large resistance between each of the three leads. I looked up testing the crank position sensor, powering it and waving something across it like a seat belt, but I haven't done it yet.

Yesterday with the Tundra 5.7 MAF after sitting for some time hood up, battery unplugged and water running over radiator. The coolant and air temp went down to 70. Techstream saw some misfires on start up, but did not throw a code.

Let it sit again until 70 degrees and tried swapping the crank position sensors. The LC did not show any misfires at startup. Immediately shut down, swapped back the MAF. Started again without misfires. I'm going to try to borrow the Tundra again this morning to see how my initial morning startup goes in the LC. The Tundra never threw a code on me.

 

[TaylorDurdan]

any further news on this? Did you get it figured out?

 

[umarali]

On cold starts I am getting multiple codes, P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308.
Sometimes all of them, sometimes a large group of them. If I start and let idle, it will eventually stumble and throw the code, the stumble will remain until fault is cleared and restarted.
If I start and begin driving, no stumble is felt, but eventually the code will be thrown.

Prior to this issue, I had the transmission rebuilt. I've since replaced plugs, MAF and PCV, all overdue.

I could use some help with troubleshooting steps.

I smell head gasket leak big time.
have you ruled out head gasket leak? low on coolant? or milky stuff on oil cap?
i have had that happen to different vehicle but same symptoms.
pull out spark plugs and get some usb camera with light (boroscope?) and look on cylinders for traces of coolant, if any moisture present there then that confirms head gasket leak. If not, atleast one thing out of the way.

 

[camino70]

any further news on this? Did you get it figured out?

No, nothing really. I’ve not had any codes in some time, I’m not sure if weather (lack of rain) or temperature (getting warm in ga) is playing a factor? Maybe I didn’t seat a connector to crank sensor or maf or ?
I still keep an eye out for varmint traces, I may need to expand that to moisture/corrosion checks too.

 

[camino70]

I smell head gasket leak big time.
have you ruled out head gasket leak? low on coolant? or milky stuff on oil cap?
i have had that happen to different vehicle but same symptoms.
pull out spark plugs and get some usb camera with light (boroscope?) and look on cylinders for traces of coolant, if any moisture present there then that confirms head gasket leak. If not, atleast one thing out of the way.

No noticeable decreases in coolant, no milk shake, no residue on oil cap. Next time I pull a plug, I’ll try to get a camera down there.

 

[camino70]

So.... we got a slight rain today and I happened to park nose down, I’m normally nose up. I have water intrusion at passenger side a pillar where it meets the oh shhh handle. It’s enough that it’s running down past the entry grab handle.

Quick check of the front sunroof drains and they both drain well. I’ll check the rears when it stops raining. It seems to be starting higher then where I’d expect the sunroof drain to slow allow entry.

The windshield is marked Toyota, but the vin is NOT etched in it like the other glass.
There is a satellite antenna and the roof rack in this general area up top.

Will soapy water help me find the entry point?