Direct Injection
 

Been reading up on direct injection and how to mitigate some of the negatives that come with it. Since our GKs have DI, this is particularly important. The 1.5L is a champ new, but for how long? I plan on keeping Foxy until she's dead and want to stretch that out.

Consumer Reports article:
Pros and Cons of Direct Injection Engines - Consumer Reports

Carbon build up is the major downfall of DI and am sincerely curious if an oil catch can (which can mitigate carbon build up due to blow by) would have any negating effects on a DI engine. Would it help filter out the crap that is floating around inside the block? I'd really like to stay away from having to dump cleaner in the tank on a constant basis.

How Oil Catch Can Works - Why Doesn't My Car Have an Oil Catch Can?

I know Bisimoto retro fitted a GK with standard valve injection, but only as part of a turbo addition. That's mostly unnecessary for those of us staying NA.

Has anyone seen oil catch cans being utilized on engines this small in a NA tune? Is it worth the investment? $140 and an hour isn't much, but every dollar counts...Thoughts?:popc:

Carbon build up happens because you no longer have fuel coating parts during the air fuel mix.

Catch can is not going to help. DI problems happen because the intake gets so fouled. Our mini cooper had tgis problem twice. Both times mini has to remove the head and cleaning using crushed walnut shells in a media blaster.

I'm trying to wrap my mind around the "you no longer have fuel coating parts during the air fuel mix." From my understanding of it, the build up is on the cylinder side of rather than the backs of the valves, which is kind of the opposite of what you're saying if I'm reading it right... No?

I believe you have it backwards ....the buildup is on the back of the valves, since there is only oily air going through them, the fuel is directly injected into the combustion chamber, instead of coming in through the intake valve. "Cleaning products" poured in the gas tank will have no effect on this "byproduct" of DI ...it is what it is....the valves are hot, and not "washed" on the backside with air/fuel mix...a drip can makes sense, theoretically, dunno if practically. Ya pays yer money, ya takes yer chances

Ok, if that's the case, shouldn't some of the vaporized oil/fuel be fed back into the intake via the PCV? Would it be worthwhile to drop some fuel additives into the line between the PCV and the intake? Seems like such an obvious issue with the technology that someone, somewhere should have been able to come up with a way to mitigate it...

While I can't speak for everyone and all areas, I'm well aware that some manufacturers have serious issues with carbon buildup causing major problems, but I have not seen a single problem or instance of the buildup in Hondas with direct injection, and we have many customers with (mostly Accords) with well over 100k on them now.

I wonder if it will ever happen, or if this is one more thing that Honda got right before giving it to the public.

As I recall, there was one person on this forum who had this problem with his '15 Fit, but that's the only one I've heard of. Mine has been fine so far, and of the many issues in the world that are causing me sleepless nights, this isn't one of them.


Not sure how a "catch can" would do that much good, as only liquid oil and what vapor condenses in the can would be "caught". Oil vapor would still pass on through, wouldn't it?

I'd rather listen to Pat Goss from Motor Week. He has stated that carbon buildup caused by direct injection MIGHT occur if you drive like the car is a high performance vehicle. Normal driving should not cause the problem. He's an experienced mechanic and has been on Motor Week for ages, both the PBS version and the cable network version. My two cents.

i think the car companies don't really care. I think they really expect that cars today are throw away products so to speak. built in obsolescence or whatever that term is.

I always wonder as well as some cars pretty much come from the factory to run rich. Does that cause problems as well?

Cynical are we? I've been buying and driving since 1958. The days of planned obsolesce are over, especially with imports. Remember the Chevys of 1957, 1958, 1959 and 1960? Now that was planned obsolesce.

It is not unusual Toyotas, Nissans, and Hondas to rack up over 100k in a relatively short period of time.

The DI/carbon build up seems to be highly exaggerated. I'm not saying it doesn't happen, but it is rare.

Yeah, I imagine it will be less than a lot of the manufacturers out there, but still, seems like a soulless move to make something you know is going to require more maintenance to sell cars.

My point is that Direct Injection is NOT a known factor in carbon buildup. I'd rather base my opinion on Pat Goss' long time experience. If you want to spend $45 plus installation, well, it's your money.

Was googling what years the fit had DI.

I just wanted to say how wrong your posted info was. Honda has now released a special machine to clean carbon finally. After denial of the issue , Honda is having a dumpster fire issue with DI and carbon buildup and injector failure.
multiple bulletins across all the models for DI injector failures and carbon issues.
I feel sorry for anyone with a DI Honda as once warranty is up your going to be paying for a set of injectors like it’s the new the tune up.
It was well documented with Toyota they used a port and DI system to resolve issues.

I'd love to see more info on this. :)

I am not familiar with this design except on the FR-S/BRZ. And I don't like it as a "fix" for the carbon build-up issue. The system-on-top-of-a-system idea is way too complicated for me. And the FR-S/BRZ forums have been reporting value train problems since the cars were introduced. But I'm not an expert.

Carbon build-up on direct injection engines is a known issue. Direct injection is simply a bad idea that was pushed on consumers to meet emissions goals. I hurried to buy a 2013 Fit because I knew it was the last of the port injection Fits.

https://cimg9.ibsrv.net/gimg/www.fit...2cfccc4cd.jpeg

i tried to upload a photo

I believe it was a Lexus that first introduced a DI to the retail market. It had DI and port injection to combat the DI issues.

unfortunately Honda is having huge issues with DI injectors failing for carbon buildup on the tips. As well carbon on the valves.
this is across all the different models amd customers are going to be paying huge bills once warranty is up.
Unless warranty extensions or recalls force them to pay for this design flaws



found a bulletin online

https://static.oemdtc.com/TSB/MC-10191759-0001.pdf

^^Thanks, Cam. :)