How To: Replacing Spark Plugs and Wires on 5VZ-FE 3.4 V6

Just changed my plugs and wires today. I used NGK Iridium plugs instead of the dual post plugs. I did not space them truck runs real good. I also got an extra 3 boots out of paranoia which I now need to return. Great post and very helpful pictures. Thank you.

 

Got the job done, thanks! Great article and the pics were a huge help. Zoomed in on the tablet and it was spot on.
Gaps were not .044, or consistent (denso). Much appreciated

 

Thank you! I just finished up this project, took me longer, about an hour and a half. All six of my plugs were Denso's, same part numbers as the plugs in the original post.

I didn't adjust the gaps on my plugs, I wasn't quite sure whether to do so or not with all the back and forth I found in this post and elsewhere. The plugs that came out ranged from .042-.046? and the new plugs were all .032-.033 I just said screw it and plugged them in. Its running fine now.

 

Very helpful but I kept trying to pry the side of the n shape on the clip for the coil. Figured out the tab is on the engine side of the clip that simply pries away from the clip. First time having to change the plugs on a '03 as I bought it used. Great tips on this. Also bought 6 plug wires. Did not know that I only needed 3 and neither did the clerk at O'Reilly. Taking back tomorrow to get the coils. Haynes is simply terrible for a repair book as it had no direction at all other than take off the boot, take out the plug and put in the new plug. Thanks.

 

how do you adjust the spacing if the plugs are off?

 

Its about time for me to do mine again.( A little bit past 30k miles) I never checked my gaps on my Denso's and never had an issue. I'm going to be gapping them this time. I'll be sure to post if I notice any difference.

 

How does one gap?

 

I dont remember the last time i had to gap spark plugs. I recently replaced the wires and plugs. If they have a cap they will already be gapped. Toyota techs do not check gapping. They put them right in. I did the same and everything is fine.

Torque them to 15 ft lbs (180 inch lbs)

 

I never have actually gapped a spark plug but I would say buy a spark plug gauge at any local auto parts store (Usually at the register) check the gap with the gauge and ever so carefully bend the spark pug electrode with a pair of needle nose pliers?...I'm sure there are a 1000 & 1 video's on Youtube on how to do so.

 

Not true. I got my plugs from the dealer (with caps), many were out of spec. Some by .01 or more

 

Does anyone have a recommendation on what brand of spark plugs to buy or is everyone sticking with OEM? 2 prong , 4 prong?

 

just installed these a couple days ago, no problems.


https://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Dautomotive&field-keywords=NGK+%284412%29+TE66+Wire+Set
https://www.amazon.com/s/ref=nb_sb_...s=NGK+(5464)+BKR5EIX-11+Iridium+IX+Spark+Plug

 

OEM, dual electrode (or, "2 prong")

 

I had been having a weird misfire for a while. It didn't happen all the time, couldn't quite determine any consistent conditions that caused it (hot/cold, under load/idle, little or a lot of throttle, etc). Sometimes it was really bad. I tried some FI cleaner just because it was easy to try. Problem still persisted so I suspected the spark. I did some searching and found this great write up. Thanks to the OP, it was extremely helpful.

Some observations and comments:

- I ordered the NGK plug wires (#4412, TE66) and Denso OEM plugs (

$8 90919-01192 Toyota Genuine Spark Plug

90919-01192). The plugs all had correct gaps out of the box.
- When removing one of the old plugs, it was giving a LOT of resistance. I was worried the threads were galled but it came out OK. I was actually quite surprised how easy and accessible everything was on this truck. A pleasant surprise for sure.
- The OEM plugs that I removed, three were NGK and three were DENSO (?) All were the dual-prong type. You could tell they were pretty worn after 135,000 miles. I'll need to check the gaps on those just out of curiousity. Not sure why they were two different brands, I know they were never changed before as I had this truck since 16,000 miles.
- Everything went back together just fine, make sure to route the wires correctly using the clips so they aren't touching each other or anything else.
- Change the M10 wrench to an M10 socket. Much easier.
- After torquing the new plugs, it can be tricky to get the plug socket off the plug rather than having the extensions come out of the socket, leaving the socket down in the hole. I shot a little WD-40 into the socket first to make it slip off the plug easier. And also SLOWLY pull the socket & extensions off the plug.

Ultimately my problem turned out to be a cracked connector in one of the boots on the driver's side. I didn't notice it when I pulled the boot off, but when I tried to get the socket on the plug to remove it, the socket wouldn't seat. Looking in the hole I noticed the connector and part of the wire in there still on the plug. I managed to get a needle-nose pliers on it and pull it off. Obviously if that was cracked or even separated before, that would be the source of my intermittent misfire.

I've driven about 25 miles now after the repairs and it seems good. The seat-of-the-pants dyno seems to indicate a little better and smoother power : )

Thanks again for this helpful write up!

 

Yep gotta love the genuine toyota parts!

$8 Toyota Genuine Spark Plug

https://www.amazon.com/gp/product/B004T1PJZ2/ref=as_li_tl?ie=UTF8

$38 NGK (4412) RC-TE66 Spark Plug Wire Set

https://www.amazon.com/gp/product/B000CJ8DC6/ref=as_li_tl?ie=UTF8

Just ordered a set of those which will hopefully go in for the 200K service

 

Sub

 

all six of the Denso (5310) IK22s i bought had a gap around 0.030-0.035. I gapped all of mine to ~0.043 before installing using this $4 tool:

$6 Lisle 67870 Spark Plug Gauge Gap

https://www.amazon.com/gp/product/B0002STS2Q/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

Truck runs great, but I did not test it with a different gap setting.

 

Ok, so this might be a stupid question but, the wires come with 3 coils but what about the other 3 coils?

Are these them?

$61 Denso- 6731201 DIRECT IGNITION COIL

https://www.amazon.com/Denso-673120...&qid=1485128456&sr=1-1&keywords=DENSO+6731201

Or are they these? What's the difference here? This one comes with 3 for less tha one, but the brand looks generic

$35 ENA Set of 3 Ignition Coil Pack 3.4 Compatible with Toyota 1996-2002 4Runner, 1995-1998 T100, 1995-2004 Tacoma, 2000-2004 Tundra 3.4L Coils Replace# UF156 C1041 GN10184 9091902212 5C1308 E679

https://www.amazon.com/Ignition-Toy...coding=UTF8&psc=1&refRID=J2V3V2E5BMHD1M3M0XE2

 

It's been awhile, but IIRC the coil attaches directly to the passenger-side plugs, and the 3 wires run from the coils to the driver-side plugs. Unlike 'way back in the olden days, the plugs fire at every revolution, not every other revolution.

 

Who gaps their dual electrode plugs before install? There seems to be a lack of internet content showing this, or how to do this...