Help!!!!!!! Need to test fuel injectors !!!!!

[magnoman]

Can any one tell me how to test fuel injectors on a Yamaha EFI 225.
Think I have pos bad one......

 

[rodbolt]

Re: Help!!!!!!! Need to test fuel injectors !!!!!

no tests really avalible with them. I just send them to Flagship marine and have them cleaned,tested and the filters replaced. you will get a printout of flow and leakage before and after cleaning.

 

[magnoman]

Re: Help!!!!!!! Need to test fuel injectors !!!!!

Thanks Rodbolt!

I brought it to the yamaha dealer for service and they said it is most likely a injector screen so they took them all off did a short test run and said that it seemed to clear up after pulling the srceens and to run it for a few days and see how it is? It's the same rough running at low rpm..... and I know that a few cylinders and not firing at idle.

 

[rodbolt]

Re: Help!!!!!!! Need to test fuel injectors !!!!!

get with your banker, you will need a loan soon.
have a nice day and enjoy your lunch.

 

[JustJason]

Re: Help!!!!!!! Need to test fuel injectors !!!!!

that's actually not true. If you have a good multimeter (and it has to be a good one ie: higher end fluke or equiv) PM me and i'll walk you through a test that works on all fuel injectors and air injectors.

 

[rodbolt]

Re: Help!!!!!!! Need to test fuel injectors !!!!!

this I gotta see, how to test for fuel flow with a multimeter.
while electrical injector failures are very rare, the clooged injector screen is very common. yamaha does not offer the screen but reccomends Flagship Marine as a repair/test center.
they will number and run flow tests at two pressure/time on settings and measure flow both before and after cleaning as well as a leakage test.then you get a printout as to before and after.

so far they have done very well for me ,usually a 24 hour turnaround.
keep playing with a half stopped up injector and you will get to post about a detonation issue that ate off the intake side of the piston crown.
if ANY dealer recomended you run without filters, I would run RUN away and never ever go back.
thats just insane.
unless the injector filter is completly stopped up it will still idle fine.
if its leaking it will idle very rich and that cylinders plug wll come out charcoal black and sooty.
a quick test for what cylinder is malfunction is to simply load the engine at about 1000 rpm and unplug the injectors one at a time and note the RPM change. the cylinder with little or no change is the one you want to look at.

 

[JustJason]

Re: Help!!!!!!! Need to test fuel injectors !!!!!

its called an inductive kickback test. it does not test for flow in a way that will give you GPH but it is a quick easy test that will tell you if you have a clogged or partially clogged injector, or if the coils inside are on there way out.
If the kickback test passes.... say, on 5 out of the 6 injectors, then you know which injector to go to. (works for air injectors to) It's better than disconecting injectors for a few reasons.
1rst, you don't load the ecu full of codes.
2nd, it will spot a problem before there may be a symptom of a problem.
3rd, it saves time and money, if an injector is suspect, you don't have to waste time (and money) sending it to a place that services injectors and waiting to hear back. That can take days, or worse if it's a weekend. The test takes 10 minutes on an outboard, and you don't have to pull the injectors.
4th.. it will tell you if there is a clogged screen as well. Fuel is a coolant, and it is what cools the injectors electromagnetic pulse coils. No fuel (low fuel) to an injector will burn one up as much as it would burn up in intake valve in a sterndrive (hint hint, jab jab =) )

Soooo spend some time and look up how to do the testing... if can't.... oh well... have fun waiting for the turnaround at the injector shop!!

 

[rodbolt]

Re: Help!!!!!!! Need to test fuel injectors !!!!!

I have tried that test, it doesnt work well with outboards. will work if its clogged bad enough maybe.
but I have seen to many pass the inductive and voltage tests that physically wont flow enough fuel fot WOT operation.
thats the biggest issue we have on outboards,fuel flow at or near WOT.
and as the F115 as most EFI yamahas run a fuel cooler the fuel will keep that tiny injector cool anyway.
if an injecter is suspect send it off.
however the ECU may store a code for an injector failure but it wont affect engine operation.
in fact we tend to see a lot of false failure codes. sometimes it says it failed 100's of hours past.
kinda like shift switch position codes.
normally set by the operator opening the throttle in Nuetral.
however now that the system has been run with no injector screens I would definatly send them off.

 

[JustJason]

Re: Help!!!!!!! Need to test fuel injectors !!!!!

hmmmm.... works great for me.
I did say earlyier that you do need a fairly good meter. I use a fluke 88V, set it to hi-res mode and enable min/max recording, hook up it, start the motor and blip the throttle a few times and then your ready to start recording the numbers. I dunno why you had trouble with it? are you using a lower end meter??

 

[rodbolt]

Re: Help!!!!!!! Need to test fuel injectors !!!!!

nope, no meter issues, as a retired navy FC I understand electronic test equipment.
most the issues wont occur until at or near full load and full throttle and sometimes it takes a few minutes at that speed and load to show up.
some I have seen run 10-20 mins at WOT before failure symtoms occur.
if its so clogged that it will show up at idle its just to quick to verify ringseal and spark then unplug injectors.
tests are all done in 15 min.
and I wont send off just one .
the problem quite often is the fact that the high pressure pumps are flow through models with carbon brushs. I dont have time to spend playing with water tests when I can simply verify ring/valve seal with a leakdown test,verify spark with my spark tester/verify rail presure then send the injectors out.
HPDI will run you nuts with the voltage and resistance tests.
the HPDI injectors operate at about 85 volts and they tend to wipe engines quick.

 

[magnoman]

Re: Help!!!!!!! Need to test fuel injectors !!!!!

Ok guys, well I sent my injectors off to sunrise injector service had them back the next day, They said they where really dirty and clogged up. I installed them. started up a bit rough then smoothed out. Put her in gear and headed out. I have about a ten minute ride through a no wake zone and that is where it was running rough.around 1k-1.2k rpm before ,know smoooth as silk! never ran so good! Got past the no wake zone and throttled up power was low then it started to kick in and out like a cylinder was cutting in and out! I was so pissed.....turned around back to habor at the no wake zone, ran smooth as silk again......Got back to the dock took out the injectors. next morning called sunrise injectors to tell him that I think one of the injectors is cutting in and out? they said that all the injectors test fine on the bench and a injector either works or it does not.... If i want to send them back he would test them again.
So I figured before I send them back i would try them once more , checked all the connectors and make sure there was no dirt anywhere. I put them back in now running rough again at low rpm worse than before but the strange mid rpm cylinder cutting out was gone?
It will run rough then for say 5-10sec clear up and keep going back and forth from rough to smooth for a few seconds?

I am about giving up. I am going to send the injectors back to sunrise to check them once more.......

It's time to look for a used 4 stroker

 

[SuzukiChopper]

Re: Help!!!!!!! Need to test fuel injectors !!!!!

Injectors are weird demons. My only real experience with them were on my GF's '87 Nissan Stanza. Her car started to run really crappy (only on 3 of 4 cylinders). Looked at everything but the injectors and on Easter Sunday last year, it just started running good again (4 days after it started to run crappy). We re-built the motor (burning oil) and I figured while we're working with basically a new motor, we'd replace the injectors. Got some 'new' ones (not remans) and almost like clock work 1 at a time started to go, almost 1 a month or every couple weeks. Used the known good ones from the old set to replace the bad 'new' ones. Last one finally went and went with a reman ($10 more then 'new') and so far 4 months later it's great. My best guess is the 'new' ones are built to be new replacements for high mileage, weaker motors and the renewed compression in the rebuilt motor ruined them. The remans are rebuilt to factory specs, hence the extra $$.

Now, I know they say that injectors either work or they don't, but I do think there is an inbetween. One particular injector would work fine until the car was driven. Don't know why but it did. They can spray the fuel (like they should), **** the gas (which effectively drops a cylinder), or not do anything at all. The pissing fuel is the middle ground I see. Thinking back to last easter, that middle ground CAN change to a full working condition under the right conditions or vise versa. Best way I found to narrow it down is when it's running rough, pull the caps on the injectors one at a time for a quick second and replace. If when you pull one it doesn't run any differently when the cap is pulled, that's the culprit. Keep in mind I did say I did this with a car and not a boat motor so I'm not sure if doing this will ruin any of the electronics controlling the injectors. I wouldn't think so but I do NOT know. Just a suggestion.

 

[rodbolt]

Re: Help!!!!!!! Need to test fuel injectors !!!!!

its very possible that you still have trash in the fuel, it tends to stick to the fuel lines then break off and clog an injector.
for some reason about the smallest filter is the injector screen.
like I say, simply placing the engine under a mild load and disconnecting each injector one at a time can isolate it to a cylinder.
however as I am an idiot pay no attention to the man behind the curtain .

 

[SuzukiChopper]

Re: Help!!!!!!! Need to test fuel injectors !!!!!

like I say, simply placing the engine under a mild load and disconnecting each injector one at a time can isolate it to a cylinder.
however as I am an idiot pay no attention to the man behind the curtain .

sorry rodbolt, I didn't see your recommendation to do that earlier! my eyes were seeing the words but my brain wasn't processing the sentences

 

[rodbolt]

Re: Help!!!!!!! Need to test fuel injectors !!!!!

if fuel rail pressure is maintaned at the correct PSI and the injectors are fireing and the ign system is working it mostly leaves a clogged injector. a filter is a filter, it can clog immediatly after cleaning if trash is still in the system.
there are 3 main systems under the hood, each has to be broken into its subsytems and tested.

 

[magnoman]

Re: Help!!!!!!! Need to test fuel injectors !!!!!

I pulled off the injector wires one at a time while runing at around 1k rpm none of them made a real difference but cyl #1 . still running very rough at low rpm.
I sent back the injectors today to get them flow tested one more time. Could this be an Ignition problem?????

 

[JustJason]

Re: Help!!!!!!! Need to test fuel injectors !!!!!

could be... could be also be a compression problem... a warning system problem etc...
im not up on the yamahammers as much as rodbolt probably is... but there may be a fuel filter in the vst as well. also... vst's are vented, find yours and make sure the vent is clean. still sounds like your running up and down on your fuel supply. if you "definitely" had clogged injectors then i would "definitely" break open the vst and check it for debris... and i would check the float to make sure it is not sticking as well

 

[magnoman]

Re: Help!!!!!!! Need to test fuel injectors !!!!!

Did a comp test all ok. What is the VST? I cleaned out the fuel filter on the motor and replaced my in line water/fuel separator.should have my injectors back on Weds will see how the tested for the second time and put them back in .

 

[rodbolt]

Re: Help!!!!!!! Need to test fuel injectors !!!!!

the VST is the tank the high pressure fuel pump draws from. it requires intake manifold removal to clean the filter.
its not hard just takes 45 minutes to access.
however if rail pressure is good, the filter is most likly ok.
but anytime I have a fuel issue with EFI I tend to clean everything from the block mounted filter to the injectors.
if ya dont the problems just keep on keeping on.
and no easy nor magick cure. its simply a matter of clean fuel.

 

[magnoman]

Re: Help!!!!!!! Need to test fuel injectors !!!!!

I will see what happens when i get the injectors back again. If he says they had some dirt in them I will try to clean the VST filter. But The motor runs so good once I am past that 1300-1500 rpm? It cruises beautiful at 4k rpm, starts right up ...don't get why at that low rpm below around 1300 rpm runs like crap???

Off this subject what is your option on the HPDI motors?