83boo2

What happened here. My v6 runner seemed bullet proof at nearly 180,000 sweet miles. Well I was at a red light on drive and it began to shake. Once the light turned green it stuttered till around 2500 rpm then ran like normal again.

I thought it was my head because I did not feel the same problem until 2 days later and same thing happened, but this time I threw a CEL...CACA!!! Well I'm going to pay autozone a trip to pull the codes. This is a periodic delima. Runner still feels fast and strong.

Any tips for the time being?

toytech76

You either have an electrical miss. Either plugs or a coil pack. Or you have an injector intermittantly going bad. We see that happen quite a bit. More than likely you will have a misfire code. Check your plugs. You may need to go to someone with the proper diag equipment to fix it for you

83boo2

wow! sounds intense..Well I do have a new set of plugs laying around. Thanks

toytech76

Make sure they are the denso k16tr-11 plugs. They should be done every 30K. Makes me wish everyone lived closer so I could help fix everyones truck. lol

83boo2

Toytech76 , Are autolites good for the runner?



Just kidding. Takes a good person to wish for people to live closer and give a helping hand! Youre a Good person..

But I do have the NGKs. I sure hope this will cure the problem. So this is a common problem? What key word could I search to gain more knowledge about this issue? I'll get back to you tomorrow to report my progress...Wait as I recall the runner had a major tune up at the dealer no more than 15k miles ago. Should I just swap out the plugs anyway?

toytech76

If you replaced the plugs only 15k ago it's probably not them. First thing is to find out what cyl it's misfiring on. Get your codes checked. Then you can go from there. Whatever cyl its misfiring on, check that plug/coil pack/wire and let me know what they look like. look for a thin black line going down the body of the plug or inside the boot of the coil. Lemme know what you find. Does it still make me a good person wanting to fix everyone's truck for a profit?? lol

mjwalfredo

Sorry to interrupt but I just picked up some Denso k16tr-11 plugs from Autozone the other day for 1.99 a piece. However, the computer there cross referenced some more expensive plugs with that part number also. I did verify that the cheap Denso plugs had the correct number marked on them. Did I buy the right plugs for a 3.4?

MTL_4runner

Yep, those are the right P/N and usually they are around $3 ea at the dealer so you saved yourself about $6.

83boo2

I went to autozone to pull the codes and Toytech76 was right on the MONEY.

P0301 - Cylinder #1 misfire detected

Well Ill search for who is cylinder #1

83boo2

I went to autozone to pull the codes and Toytech76 was right on the MONEY.

P0301 - Cylinder #1 misfire detected

Well Ill search for who is cylinder #1

jukeit

Two of us just went through a similar problem (link below), but mine was not bad enough to throw a code. Cutthroat72's ended up being bad wire. Mine ended up being a bad coil pack. Hope yours is a plug or wire. They are cheaper.

https://www.yotatech.com/forums/f2/c...roblem-132395/

83boo2

Thanks JukeIt...

Did you change out all the wires and/or coil packs? And how did you determine to change either the wire or coil packs?

jukeit

Here is the order in which I did things. In hind sight, the clue to the problem was staring me in the face on the first step, I just didn't have the experience to recognize the signs.

1. Changed spark plugs. One of the plugs had a thin vertical black line on the white part of the plug. Also that plug's coil pack's boot was brownish in color compared to the blacker color of the other two. Those were the signs I failed to recognize as a coil pack problem.

2. Changed the wires. These were 50 bucks, but had resolved the same problem for multiple other people. I would replace both plugs and wires at the same time. Save time and effort and you probably need them replaced anyway given your mileage. Hold off on the coil pack because it's more expensive and less likely to be the problem.

3. Cleaned the MAF. I actually did that a couple months prior but F'd up and used contact cleaner which contains a lubricant. Dirt and dust clung to the lubricant. Recleaned with brake kleen as suggested by toytech76 and that worked great. Keep in mind I had no code to point me to a specific cylinder. For all I knew I was misfiring in all of them and from my understanding could be caused by a dirty MAF.

4. Cleaned the throttle body. Again no code.

5. Checked for vacuum leaks. Again no code.

6. Replaced the suspect coil pack and that ultimately fixed the problem.

Adam F

Each coil pack gives spark to 2 cylinders, so if your only getting a misfire on 1 cylinder, I dont beleive its a bad coil pack.

83boo2

Amazing...I swapped in my new NGK plugs in today and BAMMM once I started it up the Check engine light was GONE. I drove around the block and noticed a huge difference. More power and a lot smoother.
The wires and coil packs seemed ok through the naked eye, but who know what it looks like internally.

I guess the true test is when i drive it in traffic tomorrow..

Old Plugs


Coil/wire


Thanks to all.....

toytech76

Yes they fire 2 cylinders, BUT it's possible for it to affect just one cylinder. If the coil is carbon tracking down the inside of the boot it will only affect that cylinder, not the cylinder connected by the plug wire. Be careful too. I have also seen bad coil packs that are tracking and someone replaced the plugs and missed that. it fixed it for a short time till the new plug also started tracking. Hopefully your new plugs solved it!

83boo2

WOW so sad threw the same code again....
well should I buy a whole set of wires or could I just concentrate on cylinder 1 (as per cel) and get a coil pack and then a wire?

I just called a toyota junk yard and the guy was telling me that it may not be a coil pack but the begining stages of a cracking head. He also mention that the 3.4l's start acting up with problems between 160k-200k. Dang this is not good.

Runner was running just fine 2 weeks ago and its been well pampered.

MTL_4runner

Ignore the guy at the junk yard completely. toytech is right on target with what he mentions and I would add that as long as you have changed the plugs and wires, then really the only two likely possibilities it could be are either a bad coil pack (as toytech mentioned) or you also may have an injector going bad on that cylinder (180k is definately enough mileage to see injectors going bad and it's a simple resistance test for that).......I've seen both causes on a misfire code. You should also look on your old plugs to see if you see any carbon traces on the insulator (white) portion of the pulg which might indicate a bad coil pack. I suspect that is probably the cause since you mentioned that changing the plug cured the code for a short period of time.

toytech76

Thanks for that! Yes..the 3.4's do crack heads between the valves, BUT you need to do some diag and eliminate all the other possibilities. Don't worry about your wires. they arn't affecting #1 cyl. Take your #1 coil pack and move it to #3 cyl and see if the misfire follows. if it does you have a bad coil. other than that i'm betting you have an injector going bad

MTL_4runner

No prob and I wouldn't tell people to listen if you didn't provide good advice. Once again I totally agree on moving the coil pack to see if that is the issue. I've never seen a case of misfire caused by a cracked head so I assume they are fairly rare, but there's always a first time. So how are they diagnosing those at the dealer now? Pressure test cooling system? Coolant block test? Other?