P11EC00 error code update

I've gotten the dreaded Cylinder #1 Imbalance error that I've cleared and had it consistently return. From what I've read here it's a burned exhaust valve that could be covered under the 5 year/60,000 mile drivetrain warranty if caught soon enough. I've taken the truck to the local dealer and they did confirm the problem and warranty coverage for my truck. Parts are ordered but not likely to arrive any time soon. They have another truck waiting for same parts for 3 weeks now.

I've learned what could be some valuable information from the service advisor who has 23 years experience with Toyota. First I asked if a new head is thought to address the problem and he indicated 'no', the heads and components are identical. Secondly, the problem isn't uncommon but no movement from Toyota to address. Third and likely most important is that according to an experienced lead tech who has worked on dozens of these failures, the culprit is a dirty fuel injector. He has shown examples to the service advisor who confirms it. Presumably that leans out an already very lean mixture thus creating excessive heat and burning a valve. I'm going to assume that injector is the last one in the fuel rail so any debris ends up there.

The service advisor did say that Toyota has updated the recommended maintenance guidelines to include adding a fuel additive every 5,000 miles. The lead tech went farther saying he would advise physically removing and cleaning that injector every 15,000 miles. I haven't checked prices but it would be my inclination to simply replace it rather than attempting to clean it. As for adding a fuel additive, I'm not impressed with that guidance as I've mostly considered such additives as snake oil.

I do want to find out what sort of filtration is in place and if there isn't something better. From many years experience with outboard motors, I know 10 micron is pretty much standard but some manufacturers (Yamaha?) recommend one micron filters. I imagine they would have to be replaced more often but that's a small price to pay for leaning out a fuel mixture and burning a valve or seizing a piston.

 

Basically there's only one filter in the gas tank, its a screen that attaches right to the pump.

Then from the pump it immediately supplies the 2 injector rails with a "y" off the tank. One to high pump, one to the port injectors.

They aren't metal threaded fuel lines so adding a filter is a bear and would require custom adaptors, and no idea what impact it may have on the feed to the high pressure pump.

Imbalance is typically injectors but we've seen heads,valves, valve seals anything really cause it. It's awful code.

Personally I don't believe a cleaner would fix it, but a physical clean is the answer, along with rotating it, even thought the DI is paired to each engine via code.

 

Thanks for the response...I forgot the high pressure pump would be in the tank, it wasn't on my previous car and outboards use 2 pumps...a boost and then high pressure. So you are correct, no dice for adding filtration post pump.

When you say 'rotating', does that mean swapping position with other injectors? How would that help?

 

Would oil catch can done anything?

 

Low in tank, high on passenger valve cover.

You said sediment was collecting possibly due to end of row in the #1 injector.

It's not simple to swap them, evenly yearly is silly but more just thinking aloud.

 

?

I was also just thinking aloud about why one particular injector was getting dirty, haven't looked at the fuel rail configuration.

That sucks that they're coded so I guess that's why the tech was suggesting remove, clean and reinstall.

 

One thing I forgot to mention that I learned was that Highlanders have the same engine but do not have this problem - not ever according to the service advisor with 23 years experience.

 

Low pressure pump is in the tank 40psi, high pressure is for direct injection, 10k+ psi. So it uses the port injection as a feed pump.

The 4runner does not have direct injection, the tacoma has more a lexus is350 engine, and the 4runner has more of a 2005 tacoma engine.

I've only seen imbalance codes on the 2gr 3.5 direct injection models, mostly highlanders and tacomas.

 

Not sure about Tacomas but other vehicles with direct injection get dirty valves and require walnut blasting the valves clean.

 

So a filter can be added between the two pumps?

I must have gotten it wrong, not the 4runner but the Highlander. I'll correct my post.

 

Anyway to know what this would cost out of pocket if you were out of the 5yr/60k?

 

Can I ask how many miles were on your truck when it failed and what grade gas you have been running ? May not make any difference , just curious .

 

I have a little over 53k and it probably started throwing this code 2-3,000 miles earlier. I have been running regular and been quite enjoying that since the two cars I sold before buying this both required hi-test. I'm considering going back to a mid grade after this.

 

Gotta call bullshit man.
Nobody runs 1 micron filtration unless in medical lab conditions. Hell, bacteria is 4 micron across!
1 micron would create such a pressure drop you would need a 5000 psi fuel pump to get any fuel to the other side, and that would only be for the first second because it would be full of dirt by then.
Good luck man.

 

Thanks , I Have been keeping an eye on these threads as my 2018 seems to fall in with the years of trucks having this issue, even though it is not very common , I’m just hoping someone can figure out what’s causing it to happen to some and not others . Thanks for the info

 

This may be good news for those with the 3.5. First step to a solution is identifying the problem. Been a lot of speculation about manufacturing defects and whatnot

 

You should do your research before calling bullshit on someone. https://www.racorstore.com/racor-hfp-43601-1-micron-pleated-paper-filter.html

 

Which is why I wanted to share what I'd learned. It makes sense to considering there's no changes to the parts that get replaced.

 

I know filtration. Do you? It is part of my job for the past 30 years. Not a rookie. The diameter of a human hair is 40 micron. Still want to debate? Still call bullshit.

 

With over 30 years as a professional engineer, I know a little about filtration. I also know how small a micron is having done the head design for a magneto-optical disk drive for platters having a 7 micron pitch. But I have no dog in this fight, I just know that at least one outboard manufacturer recommends a 1-2 micron final filter after the high pressure pump in a system that has a typical 10 micron pre-filter. You can call bullshit on them all you want, it's not my design.