Trouble Code P0306

[4x4mike]

So it looks like I have the dreaded P0306 code, misfire cylinder #6. I got a pending code on my Ultra Gauge on the way home from work and by the time I pulled into the driveway it was a full trouble code. My code reader also pulls up a P0306 and nothing else in the DTC's. I did a quick google search while I changed clothes then decided to drive it around and see what was up.

After doing a little reading and throttling I ended up at the dealer. Truck starts fine but then has a bit of a grumble. Idle is a bit low, under the regular ~750 RPMs. The exhaust also has a lub-lub sound, not normal. There is a loss of power and the miss, along with hesitation is very noticeable on acceleration (1st and 2nd gear) and driving in reverse. I've cleared the codes and under heavy throttle I can get it back, otherwise it logs as a pending.

I have a spare coil pack so I took the time to replace the middle pack (my Haynes manual says this controls the #3-6). No change. I also moved the spare coil pack to the front and rear positions with no improvement. While at the dealer I picked up new wires and plugs as they have very close to 84K on them. Visually they are fine but I figured I needed them and it would be a good way to isolate the code. After changing the wires and plugs I still get the code and there is no improvement in idle or acceleration.

I just got back from Pismo and put a flawless 700 miles on the 4Runner. I got 20.8 mpg on the way down and 21.3 on the way home. I used Chevron gas and had no problems during the trip or reefing on it in the dunes.

The remainder of my google searches talked about replacing injectors. What's everyone take on this? I'll have to go back to Bob's post about his injectors but in a simple search it doesn't look like he got the P0306 (Sean did though). Napa has a re manufactured injector for ~$60 and new (Napa brand) around ~$120. I didn't get a price check at the dealer but I'm guessing higher, if available. As important as a part as this is I'm not too hot about dumping a lot of money into the 4Runner. Just a few weeks ago I was test driving potential replacements (should have driven my wife's car there, it's on to me).

Later tonight I'll try to upload some pictures and do some more reading. The plugs looked fine, as did the wires. I couldn't see any arc traces on the coils, boots or wires. If I go the route of replacing the injectors, should I replace all of them?

https://c7.staticflickr.com/6/5270/29943456606_dbcd867a29_k.jpg

One side of spark plug from cylinder #6
https://c6.staticflickr.com/6/5674/29350846933_6c289d2965_k.jpg

Other side
https://c2.staticflickr.com/8/7770/29350848073_20b912a9b5_k.jpg

[4x4mike]

Still trying to get the kids to sleep and Camelback isn't working on my phone. Does this price seem right for a Toyota injector?

http://www.ebay.com/itm/TOYOTA-TACOMA-4-RUNNER-TUNDRA-Fuel-Injectors-3-4L-V6-2320962040-2325062040-New-/201673063731?fits=Year%3A1999%7CMake%3AToyota%7CEn gine+-+Liter_Display%3A3.4L&hash=item2ef4a6bd33:g:GwQAAOSwgQ9V6jIl&vxp=mtr

Edit: Camelback has a price of $118 for the same part number

2320962040 - INJECTOR
4-Runner; 6 Cylinder

[RobG]

Like I said before I don't know anything about 3rd gen error codes but I have been finding some good deals on partsgeek.com most of the time I buy Aisan or whatever the OEM brand is for that part. Not sure of the year of your 4runner but they have the Aisan for $106. Sometimes my wife can get the dealer to match or come close to their price.

http://www.partsgeek.com/catalog/2000/toyota/4runner/fuel_injection/fuel_injector.html

Your truck might have overheard the conversation about looking for replacement.

[4x4mike]

Sometimes my wife can get the dealer to match or come close to their price.


Your truck might have overheard the conversation about looking for replacement.

Are you saying your wife has a magic touch? I'll look into partsgeek.

My truck more than overheard the conversation. It drove me there.

[malteserunner]

I'd check compression. The exhaust sound you described makes me think of a tight valve.

Did you pull the spark plugs? If so, how did they look, color wise? Dual electrode plugs, right? Sometimes the core of the plug falls out, if they have too many miles on them.

Just throwing out some ideas.


Edit: sorry, just re-read and saw that you changed the plugs.

[4x4mike]

Plugs looked fine to me for their age and all had their electrode. From reading it sounds like injectors are the next step. What I haven't researched yet is how much of a PITA they are to swap out.

[toyotech]

Yup. Injectors. Very common on the 3.4 as it starts to show its age nowadays.

[RobG]

My truck more than overheard the conversation. It drove me there.

That is hilarious. Good luck with the repairs.

[YotaFun]

I would lean towards the injectors as well.
To add a different spin on things, when mine started to go I actually get back fire under heavy load.

If you want to rule it out, since it is the hardest one to get to, swap it out with cyl# 1.
If the miss goes at least its a little easier to replace the 1 injector since its right up front.

I had a donor engine so I went ahead an used all the injectors from it.
If you are thinking of replacing the 4Runner just go with the one, if you are looking to keep it a few more years look to replace them all or send them out to witchunter like Bob did and see what condition the rest are in.

[Bob98SR5]

Injectors. I bought 1 injector from Five 0 motorsports and it was helluva lotta cheaper than anywhere else. Running fine it seems

[4x4mike]

Thanks for the input guys. I've noticed in the past two mornings everything runs fine in the morning. My commute is about 3 miles and it's not long enough to trip the CEL. Any farther it comes back. Hesitation, stumbling and rough idle.

I've got an injector on it's way from Camelback Toyota and another coming from the eBay. The eBay one was bought under haste late at night. I'm not intending on using it as I've got a factory one on its way so it will probably go into the spare parts bag.

Avy, good suggestion on moving the injector to isolate the problem. Right now the code is for cylinder 6 which is the hardest to get to and requires removal of the most parts. Unfortunately I haven't had the time to dive into removing anything let alone putting my DDM on the injector. I'm just hoping it's the injector, and #6 and that I can stay on the road.

[toyotech]

If you got two coming. I would replace another one under that same bank.

[4x4mike]

Hadn't thought of that. Would there be any rhyme or reason as to which one? With over 180k on the clock I was thinking of just packing one along in case I'm somewhere and couldn't get one. By having the spare it would be available for any of the other 5.

The other one I have on the way will be here tomorrow and is the eBay one I linked above. It looks just like the Denso one Bob bought from Five 0 Motorsports.

[4x4mike]

Both injectors I order came in today so after I get these kids fed, cleaned and changed I'm headed to the garage. Wish me luck.

[Bob98SR5]

Mike,

Good time to check your vac hoses while everything is off.

[4x4mike]

Everything came apart and went together fine. I've had a few hoses that have had small cracks on the ends but they have been like that for almost as long as I've had the truck. One day I'll get around to tracking proper part numbers to get those hoses. All the little ones that go to the intake plenum are in good shape.

I quickly bench tested the bad injector before replacing it and it tested near what they other two replacements did. I guess this is fine because they were cold and when everything was cold the truck drove fine. It was once things heated up that my Ultra Gauge would chime and the light would come on. I replaced the one injector with the genuine Toyota one and went out and reefed on it. I probably went through a quarter tank of fuel trying to get it to hiccup and so far it hasn't. Hopefully the injector was the problem and I got everything back together properly. Total time under the hood was less than an hour.

I'll upload some pictures this evening and point out some of the things I've discovered. Hopefully it will help some others in the future.

[4x4mike]

Fingers are still crossed. I didn't get to drive around much today but I drove it pretty hard last night and a bit today. Idle and power seem spot on. No pending codes or hesitation where I would get it before.

Here is what I ordered from Camelback. $118

https://c4.staticflickr.com/6/5468/29971306651_6a844052d6_k.jpg

https://c7.staticflickr.com/6/5327/29760822830_aad3276e6e_k.jpg



From eBay. $45

https://c2.staticflickr.com/9/8539/29427887153_1e93b17ba8_k.jpg

https://c6.staticflickr.com/9/8620/29971302581_3828f46c6c_k.jpg


Side by side.
https://c2.staticflickr.com/6/5759/29971301241_633620a49a_k.jpg

Bad one on the right
https://c6.staticflickr.com/9/8406/29427881533_7a1fb30f53_k.jpg

https://c7.staticflickr.com/9/8279/29760807070_2eeac3181b_k.jpg

Like I said I used the $118 one and threw the $45 one in the tool bag I carry along with the orings from the bad one. I bench tested the bad one and it was only slightly off from the two others. The two new ones were within less than 1.0 ohm from each other. I have the readings written down but they aren't in front of me right now.

I used some jumpers and got the old one to fire so I know it wasn't totally fried. Plus when the engine was cold it would run fine. I'm thinking it metered out okay on the bench because it was cold.

All three injectors look similar and there aren't any red flags on the eBay one. I'm sure it works fine. I'll keep it as it might get me or someone else out of a jam down the road. Replacing the injector wasn't hard and can be done in a parking lot with just a few tools, none of them were specialty tools. Thanks for all the suggestions and I hope it's awhile until I have to tackle this again.

[YotaFun]

Can you take a photo of the jet side of the injector as well.
I am curious what the ports look like at the end.

I remember my moms 98 ES300 having a similar issue to yours,
I did not bring it up because the 3.0 in the ES is a different beast but seems like the injector failed the same way, when cold the engine was spot on, after warming up it was horrible.

[4x4mike]

The jet side is really hard to photograph. The injectors have the lighter color plastic covering the jets. The plastic has two holes like a little pig nose. About 1/8 of an inch deeper are the orifices, they are 4 small holes. I'm not sure if mine were clogged but the holes are so small it's hard to tell. I shot some brake clean through the injector while jumping the leads to 12v but all I did was make a mess.

I watched a lot of injector videos on YouTube and its not too hard to do. If the injectors aren't too hard to access maybe try moving them around and see if the trouble code changes, then replace as necessary.

[toyotech]

Should have threw the spare new one in as well under while the pleumn was off. Than keep the good one you replaced as a spare instead. No point in carry a brand new spare when you can carry a used good one. Oh well that's just me.

[4x4mike]

I hear ya but with my luck if another one goes out it wouldnt have been the one I put the spare in. I also didn't want to risk a cheap replacement leaking or causing other troubles.

[4x4mike]

Can you take a photo of the jet side of the injector as well.
I am curious what the ports look like at the end.



Here is the business end. I couldn't get a picture of the 4 small holes inside of the pig nose especially when it's as dirty as the used injector. This is what 17 years of spraying fuel looks like.

https://c1.staticflickr.com/9/8701/29975219472_f46183b573_k.jpg

[Bob98SR5]

wow mike, neither of mine were that dirty. not even close. j

[Seanz0rz]

Mine were not that dirty either. Check the PCV valve

[4x4mike]

PCV looks fine and still has the check valve moving. It was one of the things I yanked on when I first got the code. The one on there isn't too old but I ordered a new one. I also need to change the fuel filter. I've been meaning to do it since I bought the 4Runner, almost 9 years ago.

[YotaFun]

For reference here are my injectors and spark plugs when I pulled them out of my truck when I was having the back fire issue:
http://i829.photobucket.com/albums/zz219/Yota-Boy/20151011_153926_zpsnz8wn7ng.jpg (http://s829.photobucket.com/user/Yota-Boy/media/20151011_153926_zpsnz8wn7ng.jpg.html)

I am trying to look through my other picks to remember which cyl each came out of.
EDIT: In order from left to right 1 3 5 2 4 6

In my case my injector wasn't fully closing instead of not opening and firing.

[Bob98SR5]

I replaced the PCV gasket too, Mike. It looked fine, the PCV itself slipped in just fine, but when I removed it the thing cracked to pieces Luckily my years of playing Operation as a kid allowed me to pick it out with no problem :)