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2015 bf50 SFI not getting fuel

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Speedaemonc4

New member
Hey all I have a 2015 Honda 50hp outboard with the ago fuel injection. The boat sat for years and then I fired it up after checking fluids the other day. Started right up and ran for a bit before shutting it down. Went back out and tried firing it again to get no start. I am getting spark and able to hand pump fuel to the low pressure pump, replaced that but still no start so I put the old one back in. Replaced the high pressure pump and when the key is turned on I hear it kick in. Still won’t start so I pulled the high pressure line going to fuel injectors and it did not have fuel fuel in it. Any help would be hugely appreciated!
 
Hi,
Lots of problems with the pump grommet on these.

Read post #22 of the thread

BF50D Fuel pump issue

Hello, Got my boat in the water yesterday and on its mooring. Went out today and was just about past the harbor and it spluttered and died. Had my friend tow me back to the mooring. The primer bulb was soft and I notice no noise now when I turn the ignition on like the pump isnt engaging...
www.marineengine.com
 
Thanks a ton for the advise. I pulled the pump system back and and found that the previous owner had already cut the grommet. Put it back in and tried something new. I turned the key on so the HP pump would charge, then turned back off, then on, then off... Did this for a little bit and then found fuel shooting out the line that goes to the rail. I reconnected it and charged it a few more time, then when i tried firing the engine it would fire a couple cylinders and then stop. could charge it again and it would do the same. It appears that the fuel injectors and plugs are both firing correctly and the fuel pump is doing its initial charge but once I start cranking the engine it seems the fuel pump isnt maintaining the pressure. Have you ever seen anything like that? if it was a car it would be time to run tests on the ECU at a dealership Id think.
 
The ECM is programmed to run the pump at key on for 2 or 3 seconds to "pre-charge" the fuel rail. But it will then take away the pump ground UNTIL it detects an rpm signal. It certainly seems to me that the ECM may not be getting the rpm signal.

The problem is, I don't have SI for this outboard so I don't know the strategy for firing ignition and or running the pump.

There are 2 crankshaft position sensors...items 5 in the link below....and you might check the wiring going to those.
Although, it might take some digging to access the plug connectors and, since you say that it seems to be firing the plugs, I would think that is all good. But it wouldn't hurt to have a look anyway.


The only "cam position sensor" I find in the parts book is labeled "Pulser coil" item 10 in the link below.


I think that you maybe can get to it's plug connector without too much hassle but I don't know for sure. The wiring diagram I have shows it's two wires, one blue w/ yellow stripe and one black.

Do you have a tachometer? And, if so, is it showing rpm when you say the engine tries to run?


About all I can say is that you should verify there's constant 12 volts power being supplied to the pump via the blue w/red (Bu/rd) stripe wire.

You could then try providing ground to the pump's
black w/white stripe (Bl/w) wire while cranking and see if it will provide fuel to run the engine.

But, even if that works, all it does is prove that the ECM isn't providing ground for the Bl/w wire and more testing needs to be done. And that is going to require reading up on the theory of operation in the service manual.

I say that because, in many fuel injection systems, there is also a "clear flood" mode. The operator gives the engine full throttle while cranking to have the ECM shut the fuel pump off to clear a flooded engine.

So, even a faulty TPS could cause the pump not to run also so understanding how the system is designed is important if troubleshooting gets beyond looking for loose or damaged wiring.

Good luck with it and I hope you keep us updated.
 
Alright so quick check and yes the tach is working, it shoots up while turning the engine over. On to the next thing when I have time later today hopefully.
 
Ran more tests, The ecu is NOT providing a ground when the engine is at RPM. I verified that I was on the correct lines and when turning the key on I did detect the voltage for the pumps quick charge. I grounded out the fuel pumps ground line and fired the engine which started immediately and idled perfectly. I removed the ground and the engine died.. Looks like its going to be the hard route. lol
Will have to find something with more details at this point since there must be something preventing that ground. Im not sure about the flooding thing, when I have the engine in WOT it wont allow the engine to crank, maybe theres a way though i dont know about.
 
Yeah, I wouldn't be futzing around with that stuff until you know more.

It's now beyond my pay grade and level of knowledge to offer more things to try....although I do highly suspect that it may have something to do with one of those crankshaft position sensors. BUT...I don't know.

It's either read the manual or hook up Dr.H software or both.

At least you now know it starts and runs and the HP fuel pump is ok and isn't blocked.

Please keep us updated and

Good Luck!
 
Hi ,did you replace the HP pump with genuine or aftermarket. I had same problem & aftermarket pumps
will not work on these motors.
 
I have not been able to fix it yet, so the ecu is NOT providing the ground at rpm, you think this could be caused by aftermarket pump? It seems to
Me that the issue present before it even gets to the pump no?
 
SpeedD,

Sorry, I'm too inept to figure out how to properly attach the above thread here.

I just thought you might benefit from reading it.

If you do a search using that heading and Iceman12 in the username box it will hopefully come up for you.

Iceman did some good troubleshooting and, ultimately, replaced the aftermarket FP with a Honda original equipment one
....expensive!

You will see he also replaced the ECM. An expensive (and seemingly unnecessary) move but it's easy to see how confusion and desperation can lead down that path.

In addition, after he had apparent success using a new oem pump and the new ECM he again had problems with engine stalling associated with loss of fuel pressure a few months later.

Although, he seemed to think that problem stemmed from a low pressure fuel pump delivery.

However, he never updated that post after Ian responded to him with a suggestion.

I have no answers for what's happening with these fuel systems but would greatly like to find out.why this seems to be a recurring issue with the Honda 50....but...maybe others as well.

Iceman reported that his aftermarket pump was drawing 5 amps while his old pump, after he unsiezed it, drew less than 2 amps. That's why he chose to use a new Honda pump.

But, sadly for us, he didn't check the amp draw of the new Honda pump. Totally understandable of course...."it works! "I'm done! Back to fishing!" I get it.

I have spent some time looking into listed amp draw specifications for 40-45 psi delivery pumps from manufacturers including Aeromotor, Bosch, Holley and Walbro.
 
The amp draw for all those pumps was 5 amps when delivering 40 psi.

So, a Honda pump only drawing less than 2 amps is a wonder to me.

As Ian stated at the end of the thread "makes one wonder why they use a 10 amp fuse".

Sorry for all the verbiage but I can't help it.
 
jgmo said:
The amp draw for all those pumps was 5 amps when delivering 40 psi.

So, a Honda pump only drawing less than 2 amps is a wonder to me.

As Ian stated at the end of the thread "makes one wonder why they use a 10 amp fuse".

Sorry for all the verbiage but I can't help it.
Click to expand...
I had 2 BF50D s that had been sitting for over two years & both hp pumps were seized. I replaced both with aftermarket
pumps both motors would purge when the key was turned & start and run for 10 or so seconds and stop.
I didn't test the amp draw , but after much frustration ordered genuine pumps & when fitted both motors started & run perfectly.
 
Oh MAN! What a BUMMER!

These outboards seem to be great but this is terrible!

I have been thinking of upgrading my old 1983 Mercury 50hp on my aluminum bass boat with a Honda. The Merc still runs great but two strokes are not allowed on many California impoundments.

I at first wanted a 60hp but I've seen those have plenty of issues so I started thinking a 50 efi would do. Now, I'm having second thoughts about one of those as well.

So sorry that you're having this problem.
 
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