[Garcia9876]

I have a 3rz-fe engine 1999 4runner
I got a P0301 code the day before my truck was shaking . But I removed the spark plug and what I can do.


The picture I show you the spark plug is from cylinder #1

[T.Tech]

from the looks of the spark plug it seems the tube seals are leaking into the tube possibly causing the plug wire to short out and not having proper spark. If you have a scan tool try putting that plug in another cylinder and swapping the wire with different cylinder and see if it follows the wire, plug it remains in the same cylinder. The picture that you have the electrode isn’t visible to look at.

[enginelover]

Google brought me here when I looked up information for a P0300 (multiple misfire) and P0301 (front cylinder 1 misfire) which happened today in my 3RZ-FE with 200K miles.

This thread doesn't show what plugs to use so I will let others know Google says the spec for the plugs is probably Nippon Denso K16R-U, or NGK BKR5EYA, 0.031", 14ft-lb.

Some say never use Bosch plugs in the 3RZ-FE.
HTH

[brillo_76]

Originally Posted by enginelover

Google brought me here when I looked up information for a P0300 (multiple misfire) and P0301 (front cylinder 1 misfire) which happened today in my 3RZ-FE with 200K miles.



This thread doesn't show what plugs to use so I will let others know Google says the spec for the plugs is probably Nippon Denso K16R-U, or NGK BKR5EYA, 0.031", 14ft-lb.



Some say never use Bosch plugs in the 3RZ-FE.

HTH

Spark plugs need to be changed at the proper intervals. They dont last forever and are wear items. Standard change intervals are lower mileage then a iridium / platinum etc plugs.

Sent from my SM-J337V using Tapatalk

[enginelover]

Originally Posted by brillo_76

Spark plugs need to be changed at the proper intervals

I just tried to remove the wire and it was so stuck on the plug that first the boot broke, then the plastic broke, then the wire pulled out.

To test compression, I tried to remove the #1 (front) plug using a standard deep socket on a 12" extension bar for both 13/16ths (21mm) and 5/8ths (16mm) but one was too fat to even get into the spark plug hole (which is DEEP!) and the other isn't the right size because it's just spinning.

Anyone know what special tool and which sizes are needed to get at these spark plugs?

I can assume the cylinder head female threads are 14mm (which is what the compression gauge uses anyways) but a 5/8ths deep socket just spins and a 13/16 deep socket won't even fit into the hole opening on the valve cover.

If you need photos I can snap them but I don't know how to upload them yet.

[spartacus]

5/8 should work or you can buy the magnetic socket from parts store

[enginelover]

Originally Posted by spartacus

5/8 should work or you can buy the magnetic socket from parts store

Thanks for clarifying that it's a 5/8ths socket.

Googls says there are 3 fundamental passenger vehicle sizes.
1. 10mm threads, 5/8ths or 16mm socket
2. 14mm threads, 13/16ths or 21mm socket (but sometimes 5/8ths)
3. 18mm threads, 15/16ths or 24mm socket (but sometimes 13/16ths)

My 5/8th's deep socket is 2-1/2 inches long but it just spins so 2-1/2 inches must not be deep enough. I'll pick up a deeper deep socket tomorrow. Thanks.

Is it 14mm the threads in the 3RZ-FE engine (that's what my screw-in compression gauge is, where the press-fit compression gauge can't fit because of the deepness of the location).

I don't know if it will show up when I hit submit but in the image I just tried to upload, the yellow arrows point to where the wire loom broke, which I think is Toyota Part Number 90919-22387 ($184.99), and the red arrow points to the 2-12 inch long 5/8ths inch deep socket that turns out to be too short.

[Bad Luck]

Are you using regular sockets or spark plug sockets? Spark plug sockets have a piece of rubber in them to grip the spark plug to pull it out once it's un-threaded. When you buy the socket ask to see a spark plug for your vehicle and engine and verify it fits before leaving.

[spartacus]

Originally Posted by enginelover

Thanks for clarifying that it's a 5/8ths socket.

Googls says there are 3 fundamental passenger vehicle sizes.
1. 10mm threads, 5/8ths or 16mm socket
2. 14mm threads, 13/16ths or 21mm socket (but sometimes 5/8ths)
3. 18mm threads, 15/16ths or 24mm socket (but sometimes 13/16ths)

My 5/8th's deep socket is 2-1/2 inches long but it just spins so 2-1/2 inches must not be deep enough. I'll pick up a deeper deep socket tomorrow. Thanks.

Is it 14mm the threads in the 3RZ-FE engine (that's what my screw-in compression gauge is, where the press-fit compression gauge can't fit because of the deepness of the location).

I don't know if it will show up when I hit submit but in the image I just tried to upload, the yellow arrows point to where the wire loom broke, which I think is Toyota Part Number 90919-22387 ($184.99), and the red arrow points to the 2-12 inch long 5/8ths inch deep socket that turns out to be too short.

you can buy a ngk wire set for $40.00 amazon

Amazon.com: NGK RC-TX67 Spark Plug Wire Set: Automotive

[SaulG]

Probably have metal portion of wire ( clip to top of plug ) still on spark plug..making socket "to short".
Grab some needle nose pliers or vise grip and get it off.

[enginelover]

Originally Posted by SaulG

Probably have metal portion of wire ( clip to top of plug ) still on spark plug..making socket "to short"

That was the problem! No matter how gentle I tried to pry up on the spark plug boot, EVERY plug wire broke off at the top of the sparkplug.

That little tiny broken off metal tip (yellow arrow) was what had prevented the 5/8ths inch spark plug socket from fitting on the plug hex.

In the photo below the red arrow points to the plastic wiring loom holder that was so brittle it broke. Are they easy to replace?

[enginelover]

Here is a closer look (red arrow) at the other wiring loom clip that was so brittle it broke off at the valve cover.

Do I replace it by removing the valve cover or can it be replaced without removing the valve cover?

[UnderFire]

Originally Posted by enginelover

Here is a closer look (red arrow) at the other wiring loom clip that was so brittle it broke off at the valve cover.



Do I replace it by removing the valve cover or can it be replaced without removing the valve cover?

They're just plastic press fit you can gouge/dig them out and order new.

Sent from my JSN-L23 using Tapatalk

[enginelover]

Originally Posted by UnderFire

They're just plastic press fit you can gouge/dig them out and order new.

That's good news! Thanks.

I don't know the full history where I won't have that valve cover off until I figure out how to tell if the valves need adjusting.

Certainly the plugs were long overdue!

[Greaser]

I had a very similar experience with my own truck just last weekend.

IMO if the plug wire connector breaks off in the boot and is stuck in the plug there's a good chance it was badly degraded where the connector clamps to the wire, either partially or completely severed and arc'ing inside the boot and causing all sorts of issues.

Getting the connector off the plug is a pain since it renders the socket/extention useless, but I had luck using a large screwdriver in the end of the socket. There's risk involved here as once you drop the socket onto the plug with the stuck connector you can no longer connect the socket extension to the socket, so it's sortof stuck in there. I was able to stuff a screwdriver into the socket and loosen/remove the plug that way. Looks like you figured it out but maybe this will help the next poor sap.

With new plugs and wires (jesus I think those might have been the originals??) my codes/misfires/rough idle is gone, the truck starts, sounds and runs WAY better, so you have that to look forward to.