boltonblue

actually interesting twist with direct injection is oil buildup on the valve stems.
Throttle bodies or multipoint fuel injection would be upstream of the valves and would wash the stems on the way into the cylinder.
direct injection is only into the cylinder, so oil vapor from the PVC hits the hot valve stems and cooks in place.
no gas washing it allows it to build over time.

tof

^^ Which is why the dual (port/direct) systems strike me as the best, if most expensive fuel delivery strategy. You get the benefits of DI without the valve stem build up issues. Manufacturers will have to figure something out soon. DI engines aren't going away, due to their contribution in meeting ever tightening CAFE fuel economy requirements. Meanwhile the Internet is awash in horror stories about poor performance, excessive oil consuption, and multi-thousand dollar de-carbonization bills for "normal wear" not covered by warranty..

From the 2017 Honda press kit for the then new Si:
"For the first time in Civic Si history, an advanced turbocharged engine powers the Civic Si Coupe and Si Sedan. An enhanced version of the 1.5-liter 16-valve DOHC direct-injected turbocharged powerplant [used in other Honda models]..."
Good luck finding a fun, reasonably sporty, reasonably priced FWD, period. Never mind one with good old port fuel injection.

Scooterboy

dlq04

Hey Bolt and Mike, this is the kind video that you can sink your teeth into.

Direct Injection Carbon Buildup Issue

Why new cars are using both Direct and Port Fuel Injection.

It seems direct injection is an engineering failure if not coupled with port injection due to carbon buildup problems on the intake valves.

DI engines will build up much more carbon than PI engines, and Fuel Additives cant remove carbon on intake valves. DI engines are very sensitive to temperature. In high temperature environments, more fuel needs to be injected to reduce the temperature of the cylinder. However, the cooling effect of the injecting fuel is not good, engine limits the power output in case of overheating.

The only way to clear the carbon deposits on the intake valve is to disassemble the intake system. DI engine need clear carbon deposits every 40k~60k miles.

Some cars using both are latest Ford Mustang GT 5L V-8, some euro VW’s, most Toyota’s such as IS350 and Camry, Nissan Altima and QX50.

It’s been suggested Honda DI doesn’t have the carbon issue; something about a little bit of fuel getting sprayed on the valve while it’s open. The claim is Honda uses valve overlap tuning to get a splash of fuel on the valves to prevent build up. They have been using DI in the 2.4L since 2013 with no reported unusual build up. I've no idea if its true or not. Maybe when my 2018 CRV or the Civic's get 30k, 40k, or 50k miles..... we will know. Its not something that keeps me up nights but as you can see I did look into it. Oil dilution is clearly an issue both the CRV and Civic are dealing with (lemon laws, lawsuits, arbitration hearings, buy-backs, and thousands of owners saying they are done with Honda).

Here's a snippet from a 2.4L turbo paper back in 2013 . . . (I won't get into the other 26 pages) but it gives you a brief idea why no shade tree mechanic can fix these issues. "A six-hole multi-hole injector was positioned between two inlet valves, and the form of the spray was optimized for stronger tumble motion, realizing stable combustion with minimal cycle fluctuation due to the formation of a homogeneous air-fuel mixture."

Heyitsgary

Thank you!!! A little research got quite a few hits, including a massive recall in China and at least one class action lawsuit in the US.

The LX and Sport have Multi-Point, the EX, Touring and Si have Direct...

Maybe the Sport is my next choice? Would like to have a sunroof, but I could get away without it, and as a daily driver, the fun factor isn't nearly as important. There is almost no other choices in the class -- Mini Cooper, Fiat 500? The price point for everything else just gets out of the range I want to be in.

s2000Junky

Ahh interesting.

I spray water/meth injection pre TB into my supercharged s2000. That would take care of the this shortcoming of a boosted direct injection car then if one is up for a little fun modification. Of course then you get all the other primary benefits as well.

dlq04

Hopefully my final comment on my CR-V. This poster summed up the feeling of many owners:

So the way I see it Honda should put a HUGE disclaimer on the sticker and sales contract saying:

WARNING!

1) Do not buy this car if you live in a cold climate
2) Do not buy this car if you have the need to idle
3) Do not buy this car if you take frequent short trips
4) Do not buy this car if you like to check your oil
5) Do not buy this car if you expect any kind of customer service

tof

^^^ Makes this Honda fanboy laugh and cry at the same time.

noodels

Interesting post.
Wish people in tech would come up with a better solution for emission control.<like 3 cats so we can remove them>.

aykalper3

I had a feeling this would come up. I understand your frustration, in fact, I've directly spoken to you about this matter. I can answer a few concerns here:
First off, bringing up oil dilution is ridiculous in this thread. It is, in no way, related to @ralper 's Si not starting. There is no correlation or causation here. Fuel in the oil will not prevent an engine crankshaft from spinning.
Second, direct injection is actually a brilliant system. It allows for very precise injection timing and amount...which create less emissions, less wasted fuel, better fuel mileage and more performance. When running an engine in a loaded condition, the engine prefers to have direct injection since the fuel will atomize well and be injected into the cylinder at exactly the right time for peak efficiency (not fuel MPG, but efficiency of combustion for the amount of air in the cylinder). It is also a very flexible system; you can run multi injection (with other engine running factors) that can heat the catalytic converter much quicker, so you get less emissions and lower fuel usage. Finally, you can adjust fuel trims in each cylinder much more precisely, thus reducing propensity for knock without cause every cylinder to run rich (or lean, if the fueling is too rich for one cylinder).
Third, hot environments aren't good for any engine...in fact, even PI engines inject more fuel when the cylinder temperature is hot, mainly to try to cool the cylinder. That said, most modern "smart" engines reduce power if it senses and overheat condition, regardless of PI or DI.
Fourth, and this isn't directly related to DI systems, but the shape of the head, positioning of the valves, depth of valve opening, all influence tumble and swirl in the cylinder. These two are tuned to optimize combustion efficiency...that is, getting as much power from the fuel and air mixture that is in the cylinder. DI is neat because you no longer have to have the tumble and swirl completely mix the air and gas...now, we can inject fuel into the cylinder to influence the swirl/tumble, but have a more flexible design for enhance airflow in the intake runners.
Of course, DI does have it's negatives...noise, vibration, and yes, buildup on the valves. However, a no-start condition as described in this thread is not, in any way, caused by DI or fuel dilution.


Actually, all of the Civics basically share the same engine...1.5L Turbo, DI engine. The Type R is the only different one, with a 2.0 Turbo, also direct injection engine. The 1.5 is an "L" engine, sharing a lot of similarities with the Fit and CRZ of previous generations. In fact, it even takes some technology from the R18 engine found in older non Si Civics.

Before you nix the Civics for DI, you should know that the Fiat 500, Mini Cooper, both have DI engines. In fact, most engines now have DI...Honda, Hyundai, BMW, Audi, VW, Nissan, Mopar, Cadillac, Buick, Chevy. Yes, even the big Vortec and LS engines use DI.


To me, it sounds like this issue is with the starter motor. It starts sometimes, sometimes doesn't, which indicates a faulty starter solenoid (either frozen or corroded), or dirt/debris inside the windings of the starter. Did the starter "click" when you pushed the button? It should try to start for about 10 seconds before giving up, and, if it is a low battery issue, you'll see the dash flicker and hear an audible click (the relay contacting then losing power).