toynewb

I have a 97 4Runner with 256k miles on it and a 6Cyl 3.4L 5VZFE engine. A few weeks ago my top radiator hose cracked open and coolant was flying everywhere under my hood. One of the things that got affected were (what i believe to be) my ignition/spark wires. My check engine light came on and i had a P0306 "Cylinder #6 Misfire" code.

I erased the codes and i was able to find out that the 6th cylinder spark wire was a little loose so after i reconnected it everything was fine for awhile. But, now the problem has come back and it only seems to be a problem in the early morning when it's cold and dewy. The misfiring and spluttering goes away after i drive for 5-10 minutes and the engine warms up.

And so I believe i need to replace my spark wires as I've never replaced them before. Is this a fair assessment or do i need to look into getting coil packs and new spark plugs too? Does it sound like i'm fixing the right thing?

Also, in checking these forums i've noticed that ppl are saying that NGK are better than Bosch. Is this true? Or are OEM replacements from Toyota better?

Lastly! In looking for NGK spark wires it shows on websites that they're selling them as 3 wires, but when i look at my engine there are 6. Do i have to buy a second pack of NGK wires then to complete the 6? Here's the link below:

http://www.autopartswarehouse.com/mm...set~parts.html

Ignition Wire Set 1996-2002 Toyota 4Runner - NGK
This is a 3 wire set - 3 wires is correct for this application (one side is dirrect coil connection)

This is my first post! I appreciate all of your help!

fillsrunner4

First off thats alot of miles, has the motor ever been rebuilt or anything? i doubt thats the case as of yet just curious. As for best spark plugs for your truck the NKG's are the OEM replacements i believe. bosch are nice aswell and it doesnt matter a whole lot. i would probably go NKG or Desno personaly. As for the wires you only need the three. the coil packs are for the passanger side plugs and the three wires go from the coil packs to the drivers side 3 plugs. I would pull the plugs and check them for wear. I would also replace both the plugs and wires. i would bet if your coil pack was out it would run real bad if at all. It sounds like maybe a tune up is in order, new plugs, wires, maybe fuel filter. hope this helps some

RacerX

good possibility when its cold and dewy out that there is moisture trapped in the connector of the plug/coil wire... In high humidity areas this is pretty common if you don't use any electric grease on the connectors

pull the wires and put some electrical grease and pop them back in place... an alternative is wd40 to displace the water but if the boot is loose this will only amplify the problem...

I would also check the electrical connection to the coil for the same issue.

I would also do the items Fillsrunner4 pointed out as well...

toynewb

awesome! i'm going to buy the wires, but which spark plugs should i get? platinum, multi-ground, iridium? Is there really a huge diff between plat and iridium and then multi-ground? What are the benefits?

do you think i need a rebuild? I've never had one done since everything has been running great and this 4runner has been reliable up until this year. (Mass air flow sensor died and a few other small things) How much do you think that would cost?

RacerX

personally I use regular NGK plugs in mine and just replace them more often...

As for the rebuild do a compression and leak down test... If its good do some regular upkeep, if its bad then I would just replace it with a used motor.

MTL_4runner

Just use OEM plugs.

You should try cleaning the MAF before you replace it because a new one is big $$$$ at the dealer.

Here's a writeup for cleaning it and what to use (brake cleaner works best!):
http://www.ultimateyota.com/index.ph...6&topic=1033.0
http://4runners.org/writeups/throttle/index.html