2017 115hp efi fuel issues please help

[Amcdaniel559]

2017 mercury 115hp efi 2B469810. I believe is started as a bad gas problem. I tried to run it on what I thought was bad gas. It would start and die many times before firing and bogging out. I removed all gas changed inline filter, changed screen in fuel rail. Then ran 2 cans of sea foam at 50/50 through and it seemed to do to the job. It would start and idle and run great had 43psi at the fuel rail. Well yesterday first time out since issues it would start and run but would not get passed 4200 rpm’s at 22mph. It would normally run 5700 at 40mph. Then today started and ran fine for about an hour. Shut it down to do some swimming. Then the original problem came back. Wouldn’t start, when it did start would putter out and die. Thinking my something in my fuel module is bad. Any suggestions please help. Thank you

 

[dingbat]

Thinking my something in my fuel module is bad. Any suggestions please help. Thank you

The injectors in an EFI are sensitive to dirty fuel. A 10 micron filter or better is required to prevent down stream problems.

When was the last time you serviced the vapor separator?

The 50/50 mix of gas and naphtha (seafoam) isn’t helping. Labeled dosage to clean injectors is 128/1

You’re just flushing dirt and debris from your fuel system on to the next down stream fuel component.

 

[Amcdaniel559]

The injectors in an EFI are sensitive to dirty fuel. A 10 micron filter or better is required to prevent down stream problems.

When was the last time you serviced the vapor separator?

The 50/50 mix of gas and naphtha (seafoam) isn’t helping. Labeled dosage to clean injectors is 128/1

You’re just flushing dirt and debris from your fuel system on to the next down stream fuel component.

Thank you for the comment. My vapor separator is the fsm. I never had it serviced because the shops around my area, it’s cheaper to just buy a new one for 900$ then they wanted to charge $1400+ for the service.

You suggest new or full cleaning of fuel injectors?

It was just weird that it ran much much better after the 50/50 seafoam. (Not back to 100%) but much better. Then the gas I had in the tank was fresh with a 2 cans of seafoam to 10 gallons. Then went back to not wanting to start.

 

[dingbat]

My vapor separator is the fsm. I never had it serviced because the shops around my area, it’s cheaper to just buy a new one for 900$ then they wanted to charge $1400+ for the service.

Holy molly...... that's crazy money given the scope of the work.

You suggest new or full cleaning of fuel injectors?

Injectors should be serviced and performance tested on a fairly regular basis. Especially of the boat sits long periods of time unused

It was just weird that it ran much much better after the 50/50 seafoam. (Not back to 100%) but much better. Then the gas I had in the tank was fresh with a 2 cans of seafoam to 10 gallons. Then went back to not wanting to start.

You may have initially cleared the filters in the FSM and/or the injectors, only to flush a bunch more junk out of the fuel tank and lines back into the filters and/or injectors.

 

[Amcdaniel559]

Holy molly...... that's crazy money given the scope of the work.

Injectors should be serviced and performance tested on a fairly regular basis. Especially of the boat sits long periods of time unused

You may have initially cleared the filters in the FSM and/or the injectors, only to flush a bunch more junk out of the fuel tank and lines back into the filters and/or injectors.

Thank you for all of your help! I will be cleaning the injectors and fsm by this weekend. Another question. You do not think my symptoms sound like more than junk clogging filters and screens? Like a bad lp or hp pump or fuel regulator? Or I have been reading about shift position sensors?

 

[Scott Danforth]

start at the tank when cleaning the fuel system.

tank, pickup, anti-siphon, then fuel/water filter, then FSM, then injectors.

 

[Amcdaniel559]

I’m

start at the tank when cleaning the fuel system.

tank, pickup, anti-siphon, then fuel/water filter, then FSM, then injectors.

any tips on cleaning a built in tank?

 

[Scott Danforth]

Pull the inspection cover over the tank

Pull fuel sender

 

[dingbat]

I’m

any tips on cleaning a built in tank?

A tank or two of E-10 and a quality, 10 micron coalescing filter and a couple of spare filters.

 

[Amcdaniel559]

A tank or two of E-10 and a quality, 10 micron coalescing filter and a couple of spare filters.

Fill up with 87? Then Just siphon it out? Refill and siphon again?

 

[Scott Danforth]

Fill up with 87? Then Just siphon it out? Refill and siphon again?

no, fill up...... go boating..... when it stumbles, change filter...... go boating

refill..... go boating

 

[Scott Danforth]

Here is what I have done to clean rusty metal tanks.

with aluminum tanks, skip the muriatic acid

cut-n-pasting from past threads:

Here is what I have done in the past
simple cleaning - 2 gallons of simple green, followed by 2 gallons of boiling hot water, go for a drive down a back country gravel road at 40mph - drain
removal of fuel deposits - 3-4 gallons of denatured alcohol followed by the drive down a back country gravel road at 40mph
removal of rust - fill tank half full with vinegar (or 20:1 mix of water and muriatic acid), let sit for a week, go down the same gravel road. drain. then fill tank with hot water and soda ash to neutralize the acid content.
after rinse, repeat the simple cleaning method above and then run a gallon of isopropyl alcohol into the tank take the same drive, then drain.

also suggest pressure testing your tank.

 

[dingbat]

Fill up with 87? Then Just siphon it out? Refill and siphon again?

Do as Scott said in post #11

"Dirty fuel" doesn't necessarily mean that the "dirt" is coming from the fuel tank.

Are you currently using a good quality, 10 micron coalescing (water separating) filter to remove any dirt and or water coming from the fuel tank?

If not, you need to get one. It will remove 98+% of all the dirt and water coming from your fuel tank.

If so, when was the last time you changed the filter?
Should be done annually unless the filter has a drain on the bottom

Then today started and ran fine for about an hour. Shut it down to do some swimming. Then the original problem came back. Wouldn’t start, when it did start would putter out and die. Thinking my something in my fuel module is bad.

Did you check the fuel pressure when the motor was acting up? It very well could be one of the fuel pumps in the FSM acting up intermitantly

 

[Amcdaniel559]

Do as Scott said in post #11

"Dirty fuel" doesn't necessarily mean that the "dirt" is coming from the fuel tank.

Are you currently using a good quality, 10 micron coalescing (water separating) filter to remove any dirt and or water coming from the fuel tank?

If not, you need to get one. It will remove 98+% of all the dirt and water coming from your fuel tank.

If so, when was the last time you changed the filter?
Should be done annually unless the filter has a drain on the bottom


Did you check the fuel pressure when the motor was acting up? It very well could be one of the fuel pumps in the FSM acting up intermitantly

I did not check the to see if pressure dropped on the stumbling. I will hook up my pressure tester and that that this weekend.

Also I was told if I add any other filter other than the simple inline filter mercury runs it will restrict flow.

And I change filters a few times a year. At least 3. Recently with all my fuel problems I have been going through a lot more.

 

[havoc_squad]

I did not check the to see if pressure dropped on the stumbling. I will hook up my pressure tester and that that this weekend.

Also I was told if I add any other filter other than the simple inline filter mercury runs it will restrict flow.

And I change filters a few times a year. At least 3. Recently with all my fuel problems I have been going through a lot more.

A well made water separating filter 10 microns filtration ability that is correctly installed inline of your permanent fuel tank line would not restrict your fuel flow.

Many of these have max output fuel flow output ratings far more than your low pressure fuel pump is able to do.

 

[dingbat]

Also I was told if I add any other filter other than the simple inline filter mercury runs it will restrict flow.

In actuality, your manual say “may” restrict flow which is boiler plate language. You will have no problem with a properly sized filter mentioned above.

What micron rating is the existing in-line filter? Should be 10 micron or better for a EFI motor

 

[Amcdaniel559]

In actuality, your manual say “may” restrict flow which is boiler plate language. You will have no problem with a properly sized filter mentioned above.

What micron rating is the existing in-line filter? Should be 10 micron or better for a EFI motor

I cannot find the micron rating for the filters I have been running. They are sierra’s I just ordered them on Amazon.

 

[Amcdaniel559]

I

In actuality, your manual say “may” restrict flow which is boiler plate language. You will have no problem with a properly sized filter mentioned above.

What micron rating is the existing in-line filter? Should be 10 micron or better for a EFI motor

it says they are 20 micron

 

[havoc_squad]

I

it says they are 20 micron

You need 10 micron filter for fuel injected engines. 20 microns is for carb'd engines.

 

[Faztbullet]

Chemicals and cleaners WILL NOT clean filters in injectors, it will cleanup the fuel system but it all ends at injector inlet. Injector will need pulled and screeen and o-rings replaced.. Need a kit like below