Stalling Yamaha F150

[Sparkieboat]

I really hope that motor runs like it is supposed to...I also wonder how an injector short could effect the 5V side of the system..but I guess anything is possible, I have seen some weird stuff before. I am still waiting to hear back from the boat shop, where I dropped my boat off last week. let us know what happens.

[99yam40]

Sorry I can not figure out how to combine the threads either

I believe only the mods can do it

"Moderators oversee specific forums. They generally have the ability to edit and delete posts, move threads, and perform other actions."

[200090tlry]

Good news rodbolt17 is here

Only mechanic I trust fully! I would hate to be in your shoes dealing with inferior mechanics. Water pump issue would be easy to figure out if it takes them three try's id really start to wonder.

[rodbolt17]

you got peed on and now your singing in the rain.
the ign coil primaries,the fuel pump AND the injectors are all powered up by the main relay NOT the ECU, at key on power.
the reference voltage,5V, for sensor use comes from a 5V power supply IN the ECU that steps the 12V input to the ECU to 5 volts for sensor reference.
had the ref voltage been low then every sensor on the engine with an orange wire would have had in range failures to a failure code.
at a minimum your TPS,Baro, and map circuits would have shown low feedback voltages if the 5v ref was low.
anytime the key is on the injectors,fuel pump and and ign coil primaries have 12V applied engine running or not. this 12V does NOT come from the ECU.
the ECU simply completes the ground path as nessasary for device operation.
its a dirt simple easy system.
and yes I know that tech, wont state any opinions.

[Sparkieboat]

and yes I know that tech, wont state any opinions.

says it all right there....
we need a master forum tech to combine the two threads..maybe they can call this Walker guy..I am sure he could do it.

[Piscator]

Educational. Really hoping someone get's it together over there.

One thing I got out of this thread was the idea to twin up a pair of 2 micron Racor's (in parallel) boatside and then install an N2K sensor to read rail pressure and display it on the console display, same as oil pressure.

Actually, I think this engine is rather simple. Certainly the fuel system is the Achilles heel. Maybe a lift pump in the fuel tank feeding a high pressure pump to feed the rails. Like automobiles. But that ain't likely.

[99yam40]

we need a master forum tech to combine the two threads..

Looks like they took care of combining them

[Sparkieboat]

he must not work for Yamaha?

[boatmangc]

[Sparkieboat]

ok Sierra, i need my monday update...I still have not heard from the shop that currently has my motor.

[high sierra]

Stalling Yamaha

I picked up the boat Thursday and in the
test tank it seems to run OK. I'll find out tomorrow when I go out fishing.
Some interesting facts are: They spent close to 200 hours between the mechanics and the tec (verified by the shop) working on the motor. At the current rate of $85 an hour that comes to $17000 dollars. Remember they had it for 3.5 months. Parts that were paid for by Yamaha came to $4000 . There was even a bag of used parts and injectors in the console they forgot. All told that's more than the motor cost new.
The shop has decided they are not going to take on large motors until they get the necessary tools and get their personnel trained . Until the tec got involved they didn't make much money.
Tomorrow, Tuesday will tell the tale. high sierra

[Sparkieboat]

good luck..I hope it runs it perfectly and never gives you another issue. please give report after first run.

[rodbolt17]

so I guess they are not going to sell the F40 and up engines.
they are EFI as well.
sounds like someone had a parts chunking festival.
first thing you do when testing the EFI system is verify engine mechanical sealing ability.
then monitor can I keep fuel pressure in the rail at the failure speed and load.
then monitor the laptop at the failure speed and load.
remember ro can save and record and graph the last 13 minutes of run time for playback later.
while its nice if a code jumps out at you it rarely does.
however if you understand why each sensor is there and how it affects ECU outputs you can look to see if sensor inputs to the ECU are about right for the failure.
its even more fun after the backyardigans have had a go with it.
but thats when its actually most enjoyable.

[99yam40]

There was even a bag of used parts and injectors in the console they forgot.

The question is are they good used parts
Hope you do not need them

[Sparkieboat]

them injectors are around $200 bucks each..maybe you could sell them on ebay and get some compensation for your troubles. Waiting on a test run report...hope all went well. still no word from my mechanic.