bob200587

I don't believe there is a need for mods to justify a switch to iridiums. They last longer, and my engine ran smoother and was more responsive.

I think that for a 4cyl it's definitley worth it....a 6, I can see it being a little too expensive

mkgarrison5

just talked with a guy i know at toyota and he said with the 3.4's younger than 04 or 05 or so should stick with regular densos.. he said he has seen them last over 100k miles and insisted that getting the iridiums are a waste of money in those older generations. he has an 02 tacoma also and he put both kinds in for 3k miles brand new just to see if there was a difference.. he said no difference at all that he could see as far as performance and gas mileage

Speedy

I felt these same characteristics in my 2002 3.4L. It is NA, has the deckplate and ISR mod done.

I dont' think the stock plugs would last 100K. In my 4Runner they were pretty foot ball shaped at 60K.

I'm going to track my gas mileage over the next few months to see if the AVG MPG increased at all. I keep it in a spread sheet and can quickly do average calcs on it.

Also, if you get the iridiums at O'Reileys they're actually only about $1-$2 more per plug than standard NGKs. I paid $6 a plug for the NGK Iridiums for a total of $36.

Hoopster

I'll second sparkplugs.com, the original replacement Densos were under $3 a piece. My originals may have gone 145,000 miles. I contacted the original and only owner of my 4runner and he said they worked fine so they were never changed. I should try to post a pic of how badly the center electrode was worn. It's amazing it ran so well.

MTL_4runner

The stock dual electrode plugs shouldn't ever be left in there for 100k miles. You won't really notice much of a difference running either plug so I prefer to stick to the cheaper ones that I can replace at will without hurting the wallet too badly. I have iridiums in my 2002 Honda Civic (that's actually the stock plug for that car too by the way) and they are beginning to feel like they need to be changed, but I'm alot more hesitant because they want like $20+ per plug up here in Canada for those. Like I said, I just run the stock dual electrode Densos, but I don't think anyone could fault someone for running iridiums N/A or not since the performance is pretty well moot as long as you're good at staying on top of maintenance.

mkgarrison5

densos are the best plugs on the market period... for their ignition systems i guess i should add

Siciliano

OK guys- The coils came and I changed the plugs back to stock. Still the same symptom. Runs like a fouled plug. I removed the ground on the battery to turn off check eng. light. It has not come on again but still runs like original problem. Whithin a 10 sec period it does it 2- 4 times on and off. When I give it the gas it "seems" to not be doing that until I let off. Any thoughts? Whats next? Do I have an igniter that I have been reading about? Thanks for all your help. S

MTL_4runner

Ok, so to clarify, you now you have the original dual electrode Denso plugs in there?

Have you gotten another CEL yet?

Did you swap the potentially "bad" coil with another one? If not you should do so. The other option might be to take one of the new coils you got and swap it with the "bad" one and see if that makes any difference.

Siciliano

Jamie- Thanks for trying to help me here. I replaced all three coils with new. I will take the old ones to Toyota at a later date to find out which one(s) is/are bad, if at all. Pep boys do not sell the "Denso" brand any more but he gave me the NGK copper core multi-power plugs which, according to him, is the other brand that the Japanese use as stock. Whatever! Much closer than the plats aey! Whats next?

Speedy

Get it to trip another CEL and have it read at Autozone to see what code ya get.

There's three things that make an engine run. Air, Fuel, and spark. One of those is your issue I'm sure. The bad thing is that in modern cars a sensor can cause one of the three to malfunction. The CEL should either tell you exactly what's wrong or give you a good idea of where to look.

EDITED....

Ok went back and saw you get misfire cyl #2 as the code. See if that same code trips again. How are your plug wires?

Siciliano

When I put those Platinums in about a year ago, is when I replaced the wires. What is the igniter and its function? Do I have this? What would it's failing syptoms be in the event of a problem, if any? During the 60's and 70's and the transition to electronic ingniton and or components started replacing the mechanical, I learned that these electronic parts either work or don't work. I would assume that this holds true for my coils, igniter ect, correct? I'll be back on tomorrow after noonish. (EST) My son has a hockey game. Thanks again Jamie.

Robert

MTL_4runner

Robert, with all the coils (igniter = coil pack btw), wires and plugs brand new, the best thing would be to drive it and let it throw another CEL code for you. Then take it to an Autozone and have the code read free or get a cheap OBD II reader (sold at almost any auto store, Sears, etc) and pull the codes yourself. We could keep speculating, but that would be the easiest.


If you indeed come up with another misfire on #2 (which sounds likely from what you mention) then you should check the resistance on the fuel injector for that cylinder. The problem is that the #2 injector is on the front of the engine on the driver's side and you need to remove the intake to test it (the odd number injectors are much easier to test since they aren't covered by the intake plenum, as is shown in the link below).

Here's an idea of what you're looking at having to do to check the injector's resistance:
https://www.yotatech.com/forums/show...8&postcount=15

A DMM (digital multimeter) as shown in the writeup is easy to get (available at the same places the OBD readers are and more, even Walmart carries them) and use. If I were doing it I would have a new injector on hand ready to go in since you don't want to remove the intake more than once.

Siciliano

Jamie

OK buddy thanks.

R

MTL_4runner

Also Robert, don't throw those coils away if they test good (you can test them yourself with a DMM as well), people on here are always looking to buy them. Ebay would be another good choice and at least help you recoup some of your money back.

If you're used to working on the old 60's and 70's stuff I know the new fuel injected, ditributorless ignition, computer controlled engines seem daunting, but let me tell you that as someone that has worked on both types (the worst was back in the late 80's early 90's when they couldn't decide what computer standards they wanted to use and engines had rediculously complex carbs) I believe the computer controlled vehicles are actually easier to work on once you understand how the systems interact. Thank God the modern day vehicle's computer doesn't run on the Windows operating system or we'd all be screwed.

Speedy

Yep, I'd go this route as well.

amusement

I am not religious man ... but amen. Setting point 'dwell' and 'gap' was a brain tease back in the day. Okay, enough of this..."now get off my lawn" (chuckle).

ODBII is one of the best features to help troubleshoot problems. The best feature continues to be a skill for troubleshooting and solving problems. Getting back on track.

OEM plugs seem to work the best for me. Cost is less compared to the rest. 100,000 miles on a plug isn't bad at all.

Siciliano

Gentlmen-

Thanks so much for all the input and the link. As I was reading the procedure I was thinking to myself that it might be a good idea to change all of the injecters on that side while I'm under there. I would hate to replace one and have another go a few months from now. The right side looks a lot easier to get to.

MTL_4runner

I think that would be a very smart idea if indeed you do find one of them is bad. Taking the intake off is a bit of a pain and you don't want to be doing that more than you have to. Then send any that test good out for cleaning and keep them as spares for the passenger side when they begin to go.

Donovan

I'm going to try the Denso IK16 iridium plug. I can get them for $11.20 each. Is there any reason I should not use this plug?

mkgarrison5

if you your system isnt hyped up just regular densos 3$ apiece will do just as good and can last a good while.. i was told by a really good toyota mechanic that they are a waste of $ for years prior to 2005