Mercury 25 HP EFI OR106999 & Up Fuel Problem

[111torrance111]

I have a Mercury 25 HP EFI OR106999 (1A25203FK) & Up Fuel Problem, had the Fuel Injectors remove and serviced, replaced the Fuel Pump.

Its starts easy when using Starter Fluid but isn't getting any fuel to keep it running, Looking for an easy way to troubleshoot the fuel system.
Most of the hose have the un-removal clamps making it tough to check for fuel flow.

Also need to know what the Air Valve on the Injector Ram is supposed to do.

Any help would be appreciated.

Thanks/Jerry

 

[airshot]

Stop using starter fluid as it will strip oil off the cylinders and cause bigger issues. WD40 or other petrol lubes will work as starting fluid without engine damage...

 

[Faztbullet]

 

[111torrance111]

Did the new pump fix the problem?

 

[flyingscott]

Stop using starter fluid as it will strip oil off the cylinders and cause bigger issues. WD40 or other petrol lubes will work as starting fluid without engine damage...

4 strks dont work that way

 

[airshot]

4 strks dont work that way

You have a 4 stroke that doesn't get any oil on the cylinders ?? No matter what engine the ether in the starting fluid will strip oil from cylinder walls. However, it is your call as it is your motor.

 

[QBhoy]

Hi. The thing referred to as an air valve on the injector rail, is called a shrader valve. It’s for fitting a fuel pressure gauge into or sometimes used to bleed the fuel rail. I’ve done the latter often. To make the process of bleeding much quicker, in the event of running out of fuel or a filter change that may cause a similar situation. Also good to be able to prove the existence of fuel there too. By key on and off..with this depressed…you can expel any air in the system quickly. But be careful about throwing flammable fuel about the place, should you attempt it.
Have you made sure the fuel fittings at the entrance to the engine and filter aren’t drawing air ? Especially if you have the red tab quick connect fittings here like mine. I’ve had to deal with a perished seal or two on these in the last few years. Just with the ethanol fuel eating at them.

 

[111torrance111]

I opened the Vapor Separators and tested the Fuel pump inside with 12v from a power source, it spins just fine. Put it back together and tested again and notice I'm not getting 12v from the plug during cranking. I can't find a wiring diagram to show where this 12v comes from or how to test. This motor has an On/Off switch which I assume activate the source somehow. Still need a little help with this one guys.

Thanks/Jerry

 

[QBhoy]

I opened the Vapor Separators and tested the Fuel pump inside with 12v from a power source, it spins just fine. Put it back together and tested again and notice I'm not getting 12v from the plug during cranking. I can't find a wiring diagram to show where this 12v comes from or how to test. This motor has an On/Off switch which I assume activate the source somehow. Still need a little help with this one guys.

Thanks/Jerry

Do you get power to it as you turn the key to the first position ? Have someone depress the shrader valve on the rail with their finger (carefully) when you turn the key to first position. You should actually hear the pump run from close to the engine as you do anyway.
I take it the fuel filter is going the right direction too ? These are uni directional.

 

[111torrance111]

Do you get power to it as you turn the key to the first position ? Have someone depress the shrader valve on the rail with their finger (carefully) when you turn the key to first position. You should actually hear the pump run from close to the engine as you do anyway.
I take it the fuel filter is going the right direction too ? These are uni directional.

This is a Tiller motor, no key. Just a switch on the front Run/Stop & Pull Start.
I did add a Starter to make iit easier to crank. Swith in the Run position and cranking with no power to the plug.

 

[QBhoy]

This is a Tiller motor, no key. Just a switch on the front Run/Stop & Pull Start.
I did add a Starter to make iit easier to crank. Swith in the Run position and cranking with no power to the plug.

Ok. So given that info. I presume it’s like the newer fuel injection engines if a size that are available in pull start, with no need for a battery. This I’d also presume means that the power ti the fuel injection system is perhaps only present or generated, when the engine running ? The priming must be if a manual nature initially you’d think ?
Absolutely not sure on the workings of the concept. But I’m about to look into it for sure.
When Yamaha first brought out their 20/25 fuel injection outboards a few years ago with pull start…I did wonder how it was achieved. If there was no battery used in the traditional sense. Unless there is a small internal power supply just for this purpose? Not sure. Got me interested now though.

 

[111torrance111]

Ok. So given that info. I presume it’s like the newer fuel injection engines if a size that are available in pull start, with no need for a battery. This I’d also presume means that the power ti the fuel injection system is perhaps only present or generated, when the engine running ? The priming must be if a manual nature initially you’d think ?
Absolutely not sure on the workings of the concept. But I’m about to look into it for sure.
When Yamaha first brought out their 20/25 fuel injection outboards a few years ago with pull start…I did wonder how it was achieved. If there was no battery used in the traditional sense. Unless there is a small internal power supply just for this purpose? Not sure. Got me interested now though.

Thanks,
It looks like the 2 wire plug for the Pump leads to the computer componet, I keep thing I'm chasing a fuel problem when it could be a Computer/Elecrical issue. This site is usally pretty good at helping figure things out. I'll keep posting update until we get it figured out.

Thanks

 

[Faztbullet]

 

[QBhoy]

Thanks,
It looks like the 2 wire plug for the Pump leads to the computer componet, I keep thing I'm chasing a fuel problem when it could be a Computer/Elecrical issue. This site is usally pretty good at helping figure things out. I'll keep posting update until we get it figured out.

Thanks

I’d try to prune up the system as much as possible. What is the behaviour of the priming bulb like when squeezing ? Is the in line engine mounted filter going in the right direction ? Does that have the wee red tab quick connect fittings on it ? To make sure there is fuel getting to there at least ? If the system is empty of fuel…it will take an age to prime up again, without some intervention and powering of the pump. That fuel rail and the pump feed will be dry and need to pull fuel to them both for sure. Even on my mercruiser mpi and mercury outboard from 2016…if it’s ran out of fuel…even with that allowing me to turn the key to first position to activate the pump…will take forever, unless I’ve primed up the system, then pressed in the shrader valve in the fuel rail to let air out. It should self prime of course…but after a long long time and many many pump actuations for sure.
I’d try avoid the use of starter fluid for sure. Not so great for these modern things for sure. Can mess up sensors on the inlet too.
Can I be so cheeky to ask if the lanyard safety chord isn’t causing this ? Sorry to ask..but thought I’d check

 

[flyingscott]

You have a 4 stroke that doesn't get any oil on the cylinders ?? No matter what engine the ether in the starting fluid will strip oil from cylinder walls. However, it is your call as it is your motor.

Maybe you should learn the difference between the 2 different engines.

 

[QBhoy]

Maybe you should learn the difference between the 2 different engines.

There’s oil in the cylinder walls of both types of course

 

[flyingscott]

There’s oil in the cylinder walls of both types of course

thanks Captain Obvious.

 

[111torrance111]

I'm closing this post and reoping a new one as my issues isn't resolved and this post lost it's direction.

Most people are very helpful and all past problems resolved.

Thanks

 

[111torrance111]

Did the new pump fix the problem?

No...

Turns out I was losing the 12V going to the Pump while cranking the motor, When I check the original motor on the bench it would work fine.

I started troubleshooting the connection from the Computer to the Pump to make sure the voltage was getting all the way through and here's what I found.

If I checked the plug itself I always had 12V, but when the Pump was plugged in I had No Voltage, so I added a 12V source from the battery to run the Pump and everything worked fine.

I wasn't sure how to correct the Voltage issues, but it turns out that was the problem.

Jerry

 

[Faztbullet]

ECU fuel driver problem