Fuel injection help please! Any 4 stroke techs?

[Gary H NC]

This is a 2005 Yamaha 90hp, F90TLRD,4 stroke.
It had a ton of water in the gas. Cleaned all lines,tank,replaced filters now no pulse from the injectors.
Injector pump is working but the injectors themselves will not fire.

Any info on what else could be checked??

 

[Gary H NC]

Re: Fuel injection help!

Re: Fuel injection help!

Bump...............anyone?

 

[rodbolt]

Re: Fuel injection help please! Any 4 stroke techs?

unplug the injectors. with key on engine off check all injector connectors for 12V on the yellow/red wires.
the other side is the ECU switched ground side.
if all injectors have 12V,unplug the ECU and check the ground side wires from each connector to the ecu.
any time the key is on all yellow/red wires will have 12V.
its also possible the injectors are stuck.
use a jumper lead to connect an ingector pin to 12V positive,like the battery cable.
use another jumper and attach one end to ground and lightly tap the other end on the other injector pin.
you should hear the injector click and rail pressure drop.
no click or no drop when clicking indicates a bad/dirty injector.

 

[Gary H NC]

Re: Fuel injection help please! Any 4 stroke techs?

Thanks Rodbolt!

I did test the voltage at the injectors while cranking the engine. .84 volts with the meter.( less than 1 volt? )
I was not sure how much voltage the ECU was supposed to supply so i did not jump 12 volts to the injector pins.
So,it sounds like an ECU problem?
I will try the test like you stated with just the key on and see but i could not read 12 volts on those today.

I was thinking along the lines of stuck injectors but being its all 4 of them i overlooked that possibility.

This motor was sunk in salt water then rebuilt by a dealer before this guy bought it.

 

[rodbolt]

Re: Fuel injection help please! Any 4 stroke techs?

if you were checking across the injector pins,cranking, loaded then all you will see is the voltage drop of the injector.
its an inductive device similar to a solinoid.
anytime the key is on 12V is supplied,the ground is switched(connected) by the ECU usually measured in a time period of milliseconds.
water will cause the pintle in the injector to stick shut as will excessive sitting and not running.

 

[Gary H NC]

Re: Fuel injection help please! Any 4 stroke techs?

Yes,I was checking across the pins and not to ground so that makes sense as to why i wasn't seeing 12 volts.
When i pulled the fuel rail and injectors off they did look rusty on the tips.

I will test again tomorrow.
This boat had been sitting a long time with the fuel loaded with water.

When i drained the tank it looked like milk.
I have replaced all the lines and filters and have a remote tank with clean fuel hooked up at the moment.

Will it hurt to soak the injectors to see if they free up?

Thanks for the help!!

 

[rodbolt]

Re: Fuel injection help please! Any 4 stroke techs?

most likly your gonna send the injectors out.
if you wish to try soaking insert the injectors into a box top with holes cut in it.
fill each injector filter with combustion chamber cleaner.
toggle them on the bench with jumper leads and a battery.
they are not continuous duty so tap the ground side against the negative battery terminal.
you will hear the injector click.

 

[Gary H NC]

Re: Fuel injection help please! Any 4 stroke techs?

Thanks Rodbolt!
Heating the shop up now and getting ready to pull them off.
After i enjoy another cup of coffee....

I will post back what i find.

Man it is nice to have internet in my shop.Got it up and going a couple weeks ago..
Saves me from running to the house to look up stuff and be on the forums...

 

[rodbolt]

Re: Fuel injection help please! Any 4 stroke techs?

ill be at the shop in a couple hours.
sucks but I had 8 updates for parts smart,parts manager pro and EPC offline.
so far 7 updates mostly work the 8th is killing me.
but I have to have the parts computer back up by monday.
somehow I got nominated as the updater dude.

 

[Gary H NC]

Re: Fuel injection help please! Any 4 stroke techs?

Lucky you Rodbolt...Maybe thats why they pay ya the big bucks....

I have the injectors soaking.
The voltage test to them was good.

The tips are rusty looking so i bet they will need to be sent off.
So far none of them will click with 12 volts.

Called the customer and expected him to be shocked at the quote but he was fine with it and added more stuff to the repair list.

The trim pump motor is locked up too...

 

[comptrw]

Apologies, I will !

 

[99yam40]

Re: 2006 F115 Fuel Injector Problem ?

Re: 2006 F115 Fuel Injector Problem ?

Start a new thread for your problem. It is a rule on the forum and makes things run better.