Injector Failure Question ??? Attn: Mods

[svfetter]

There has been much discussion on here about the failure of an injector on a DI or a Etec motor being the reason for an overall engine failure and requirement to rebuild or supply a new powerhead.

My question revolves around how the injector fails. I realize there is no way to predict or in some cases know why. But when a injector fails does it just quit putting fuel into the cylinder ??? If so, then there would be no damage to the cylinder as it would still be getting oil, just no fuel, basicly a dead cylinder. Am I wrong ??

It seems that what must be happening is that as part of the result of the failure, the cylinder goes lean either from an internal failure or possibly from being clogged or gunked up. We all know what that lean condition will do !!!

Seems like to me if the injector worked or did not work 100% in either case, repairs would not have to be so extensive. If an injector just went dead with no lean condition, Then only the injector would have to be replaced.

If my theory is correct, do you repair guys ever see a failure where just the injector needs replacing ?? If my theory is off, am sure the experts here will correct me.

Just Wondering

[Danrude]

On the DI engines the fuel and oil are mixed before going into the injector, on the E-Tec the oil is injected directly into the cylinder.

[svfetter]

Hi Dan,

Thanks for your response. So what about all the small oil lines which seem to inject oil in areas just behind the throttle bodies? Are these not enough to keep the piston and bore lubricated enough in the case of a injector not working ??

I realize if an injector goes lean it may not matter how much oil is present.

[nola 521dvx]

Correct me if I'm wrong but isn't it more accurate to say that a small amount of oil is mixed with fuel to clean the injector in a DI motor; the majority of the oil is injected ahead of the crank?

In respone to the original question, I've had the same thoughts after just finishing a rebuild caused by a bad injector - a partial failure (ie lean condition) seems to be the problem; total failure would cause you to stop running it presumabky without any damage. One would think there would be a way to incorporate temp sensors into each cylinder to warn us of impending melt-down, or a knock-sensor alarm for detonation (?), guess it adds cost and complexity.

[stevousa6]

My 2006 200 H.P. E-tec needs a new engine block and powerhead. I did not know if you read my topic relating to this, but my theory has to do with exactly what you are talking about. It was my number 6 cylinder that we see the aluminum shavings, all others look excellent. My mechanic said that the sixth one on e-tecs for whatever reason (distance?) seem to be a common problem. I bought my boat in March of this year and had no idea of the work that had been done on it other than a recall by BRP of a power head. But it appears that the previous owner new of fuel related problems, becuase my injectors on it now were not the original ones, as well as other parts. My opinion is that this motor was not built right. I know others will disagree, but after speaking with my mechanic, we both came away thinking that the problem still has not been determined which bothers me even more. He also mentioned about the design of the etec's as far as how each cylinder recieves oil continues to be a major problem for e-tecs.

[stevousa6]

Also, with what you say about warnings or some type of sensor. I sure as hell wish that would have happend to me. All that happend to my motor was I went from about 60-0 mph and now its been in my garage or the shop for the past 5 weeks. When it first happend, I didn't think I needed to rebuild my motor, because there was no warning. But that goes back to the point you made about some kind of alarm. When the computer was hooked up to it, four hot engine alarms appeared, none of which I had seen in my 3 and a half months of using it.

[gilly]

lean fuel or no oil is what blows the engine. the fuel injector must supply pressure and volume. the idea is good but reality is bad because that is too much to ask of the injector until they can sense a lean condition. open or shorted injector fault is useless except for helping pinpoint a miss.
the oil pump senses a pump failure but not a clogged hose. etecs run great when working right but i'd be scared to own one out of warranty.

[stevousa6]

Well put. Mine ran better than any motor I had ever owned, but when the warranty expired in May, it decided to have a total meltdown.

[svfetter]

Good Discussion Guys.

Guess it is safe to say that these engines virtually never have a injector go out 100%. Just get lean and cause a bigger failure

I blame all of this on the Gov with all these regulations which need not be applied to outboards anyway. You never heard about all these issues in the good old days when everyone was running carbs and mixing oil. Granted these new engines do run better in many respects, but i am not sure it's worth it.

I had a 85 XP150 which was a great engine. They were a little thirsty on fuel, but there are many times when I wish I had that old cross flow back. A good one of those set up today would perform well and run just as fast as a new Etec of the same HP

Unfortunately, the good old days are gone in more ways than one.

[nola 521dvx]

IMO regulations should apply to outbopards - after all they are way dirtier than auto engines (4 mpg vs 25 or better mpg). I'm happy to take steps to leave the environment in better shape for my (and your) kids, with improved reliability to boot. Would you honestly rather we didn't have progress in our technology? We'd still be driving carbed cars getting 10 mpg (@ $3 a gallon) and breathing smog. I thank the Gov for that.

On the other point, I don't know whether injectors ever go out completely themselves but I do know that the EMM can develop problems that prevent injectors from firing 100%.

[stevousa6]

I am pretty sure that wasn't his point. The point is, why do I have to be in the hole 10,000 plus dollars, when my older 2 strokes were way more reliable. In this day in age, why can't we manufacture something of quality while keeping the environment clean. With today's technology its unexcusable why things don't last like they should.

[Mr Limpet]

I wonder if a lot of the DFI melt down problems are not fuel pump/ fuel pressure regulator related. Low fuel pressure can result in a lean injection to a cylinder and BOOM. These motors have an electric fuel pump that must keep constant pressure to all 6 injectors via a working regulator. I wouldn't run a new power head without changing the fuel pump and regulator. I hope you get to the bottom of this problem.

[gilly]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by Mr Limpet &raquo;</td></tr><tr><td class="quote">I wonder if a lot of the DFI melt down problems are not fuel pump/ fuel pressure regulator related. Low fuel pressure can result in a lean injection to a cylinder and BOOM. These motors have an electric fuel pump that must keep constant pressure to all 6 injectors via a working regulator. I wouldn't run a new power head without changing the fuel pump and regulator. I hope you get to the bottom of this problem.</td></tr></table>

you need to investigate etecs a little more.

[nola 521dvx]

In my experience older 2 strokes were less reliable - I've had more carbed motors blown than injected ones in my ~25 yrs of boating. Second, while there may be circumstances when it costs 10,000 (new block plus crank) I think that figure is a huge exaggeration in general - just finished a rebuild of a DI motor myself, $2500 parts at dealer prices (significantly less if purchased online). I agree that the newer motors should be even more reliable - for instance, I wouldn't worry about the injectors leaning out on a car and causing it to blow a) because I suspect the injectors almost never fail that way (improved technology, better quality control) and b) if they do fail the vehicle computer will alert me to the fact. Seems that the biggest problem with our injected outboards is there is NO warning system to detect an injector with failing flow.

[gilly]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by acatli &raquo;</td></tr><tr><td class="quote">In my experience older 2 strokes were less reliable - I've had more carbed motors blown than injected ones in my ~25 yrs of boating. Second, while there may be circumstances when it costs 10,000 (new block plus crank) I think that figure is a huge exaggeration in general - just finished a rebuild of a DI motor myself, $2500 parts at dealer prices (significantly less if purchased online). I agree that the newer motors should be even more reliable - for instance, I wouldn't worry about the injectors leaning out on a car and causing it to blow a) because I suspect the injectors almost never fail that way (improved technology, better quality control) and b) if they do fail the vehicle computer will alert me to the fact. Seems that the biggest problem with our injected outboards is there is NO warning system to detect an injector with failing flow. </td></tr></table>

ATTENTION PLEASE : etec injectors build the high pressure, not the pump. that is the critical difference from all other injected engines. also, 4 strokes have an intake cycle of cool air even if they don't get fuel. 2 strokes only have fuel to cool the piston. that is why it's critical.

[dhagemei]

uhm? My experience with powerhead failures of all brands whether carb or injectors are caused by situations outside the motor cowling, that is about 80% from my experience. There is one more point that i thought ;as fuel heats up in fuel rails or from the high psi compression in omc Di , we get lean burning . Others have fuel coolers in the engine, what has omc provided in this case? input much appreciated. Thanks.

[SEAHORSE]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by dhagemei &raquo;</td></tr><tr><td class="quote">
Others have fuel coolers in the engine, what has omc provided in this case?
</td></tr></table>

You do not know much about FICHT or E-TEC even though you seem to post a lot about them.

Both FICHT and E-TEC have used fuel coolers since the first models were introduced in 1996.

[dhagemei]

I did attend FICHT back in the 90's( full 5days on this motor only). E-tec and ficht are a rarity in our area, so not much hands on, so forgot a few things here and there.

I was commenting on a theoretical point that the compression of fuel on the di injectors causes the fuel to get hotter just like a turbo charge r or air compressor heats up air. so, hotter fuel (leaner burning mixtures) entering combustion chamber even though it was cooled before. Yami (hpdi-up to 1000psi) seems to be experiencing high temp. meltdowns too. just kicking ideas from other angles.

[stevousa6]

Good discussion by all. And trying to learn as I go. Back to whoever said 2500 dollars for a rebuild. My motor is a 200 hp motor. Just to pay labor to get the job done would be over 1000 I figure. I wish 2500 was the damage. Anyways what about the S.A.F.E. mode on the e-tecs? Does this save motors?

[stevousa6]

Also what about 225 h.p. fuel injectors on my 200 h.p. motor? Would that cause a problem, and would it contribute to my motor running better until total meltdown?