Evinrude Fuel Pump question

[racerone]

And what pulls the fuel through the jets ??

 

[PensacolaJason]

And what pulls the fuel through the jets ??

Vacuum, I believe.

 

[PensacolaJason]

I could be grasping at straws, but I took another crack at the VRO pump. I opened it up and found that the rubber gasket on the one side was way off center. Could this cause enough of an issue to create my problem?

I attached a before and after picture of the misaligned gasket.

 

[racerone]

Well there is something missing on your picture of the pump.--------The pin that holds the brown rubber bit , where is it ???

 

[PensacolaJason]

Well there is something missing on your picture of the pump.--------The pin that holds the brown rubber bit , where is it ???

It was on there. I removed it before snapping the picture.

 

[racerone]

So what did it look like BEFORE you took that pin out ?

 

[PensacolaJason]

The black plastic washer with the metal inner washer was centered with that pin and the brown rubber washer was off centered like in my photo.

 

[Crosbyman]

"Yes, I ran it on a reliable portable tank setup I have with fresh gas, same issues. "​

have you tried holding that fresh fuel supply above the engine while it idles ......use a good hose/bulb

see if it dies out ...or runs longer

if it does try the throttle plate move as in the video ... post results

post results

 

[PensacolaJason]

I've got another update. I had some time to put the fuel pump back on the motor. I ran it a few times and it would idle for a few minutes then it would die. I primed it again and removed the fuel-out hose that supplies fuel to the carbs and cranked it again. It idled and no fuel was coming out of the fuel-out hose from the pump. I recorded what was happening. I think this pretty much confirms that either my fuel pump is bad or there is no pulse coming from the crankcase to operate the pump, correct?

https://www.youtube.com/watch?v=VjbZcUF5PT8

 

[oldboat1]

Don't think I've seen a fuel filter mounted quite that high -- usually see them low(er) on the transom, between the tank and motor. Maybe that's an issue.

 

[heypawpaw]

In one post you said:
I feel like I’ve troubleshot just about everything and fuel delivery seems to be what it always comes back to. Another : I rebuilt the pump with a new omc kit and re-ran all new fuel lines everywhere and checked all connections. Another: I can get it to idle okay, although eventually the motor will die and the primer bulb will go soft. If I try and give it any throttle it dies almost immediately, as seen in the video. Did you try pumping primer bulb while running to see if it made a difference? Why would primer bulb go soft if fuel pump is not pumping fuel? Did you check hose connections at tank and motor and if so, how did you check them and what about check valve in primer bulb? I would give these more attention.
Double check all throttle, carb, spark advance linkage connections. { Had a plastic ball & socket connection on spark advance linkage on a 50 hp rude come apart while fishing one day. Engine would idle ok but every time throttle was increased engine would bog and die just as yours does. I had a fit and jerked throttle lever back and forth, then my buddy says what's this thing flopping around on side of the engine? Went to back of boat snapped the ball back in the little socket and cranked it up and problem solved.} As Racerone said more fuel without spark advance is a no go.

 

[PensacolaJason]

Don't think I've seen a fuel filter mounted quite that high -- usually see them low(er) on the transom, between the tank and motor. Maybe that's an issue.

You mean the Fuel-Water separator? It’s been mounted there since the last motor (120hp Johnson) on this boat and it never caused an issue.

 

[oldboat1]

Height aside, I believe the Racor-style filter is usually installed between the tank and the engine, with the primer bulb between the filter and the engine -- can't tell what set-up you have.

 

[Crosbyman]

"" It idled and no fuel was coming out of the fuel-out hose from the pump….""


looks like a dead pump….
options….

- bad defective pump
- vacum pulse not reaching the pump (vacum pulses not reaching the pump diaphragm wrong misaligned gasket or something )

why not clear up 99% of the issue … feed gas directly to the fuel distribution going to carb or carbs (whatever) and see if it runs or accelerates properly

has suggested feed it gas from a source above the engine for a few minutes while you test the engine



if ok….. work the pump issue if you prime the bulb and gas flows out that hose in the video you have no obstructions ! Great !
​

disconnect the engine side fuel connector and blow air backwards in the pump's fuel outlet hose (the one on the video with no fuel coming out) .

If air flows in the reverse direction the pump's one way check valving function is defective preventing the pump from sucking gas from th tank


just mho​

 

[PensacolaJason]

"" It idled and no fuel was coming out of the fuel-out hose from the pump….""


looks like a dead pump….
options….

- bad defective pump
- vacum pulse not reaching the pump (vacum pulses not reaching the pump diaphragm wrong misaligned gasket or something )

why not clear up 99% of the issue … feed gas directly to the fuel distribution going to carb or carbs (whatever) and see if it runs or accelerates properly

has suggested feed it gas from a source above the engine for a few minutes while you test the engine



if ok….. work the pump issue if you prime the bulb and gas flows out that hose in the video you have no obstructions ! Great !​

disconnect the engine side fuel connector and blow air backwards in the pump's fuel outlet hose (the one on the video with no fuel coming out) .

If air flows in the reverse direction the pump's one way check valving function is defective preventing the pump from sucking gas from th tank


just mho​

Here is what I have tried today:

- I removed the pulse hose from the fuel pump and idled the motor and could feel pulses of air.
- I removed the fuel filter and ran the motor. Engine stalled after a few minutes.
- I removed the fuel outlet hose that leads to the carbs and blew as hard as I could. I could not get air to flow backwards.
- I ran the motor with a portable fuel tank above the engine. Engine still stalls after a few minutes.
- I purchased & installed a non-oil conversion fuel pump (pictured below) and ran the motor. Engine stalls after a few minutes. Should I be able to blow backwards through the fuel outlet on this new fuel pump? I am able to blow backwards into the fuel outlet and can feel the air coming out of the fuel inlet.
- I installed a clear fuel line from the fuel-outlet to the carbs. I could see that an occasional squirt of gas would come from the pump, but generally nothing was pumping.

If I start to pump the primer bulb as the motor begins to die I can get it to idle back up.

Is there any device or gauge I can purchase that can measure the pulse coming from the Pule Limiter? At this point I am wondering if there isn't enough pulse coming from the motor. How much pulse should be coming from that pulse hose on this motor?

 

[Crosbyman]

strange.. hand pumping "brings it back to life" yet a fuel supply held above the carb does not keep it going.

presumably you did "prime" the fuel feed going "down" to the carbs ….if not the normal siphon effect would not have started on its own to feed the carbs

ok so looks like weak pumping unless other opinions come up.

personally not familiar with what the "pulse limiter does" … i'll let the pros help out on this one but if you google

"E130TLEDM pulse limiter" al sorts of info come up and seems pulse limiters can go bad from carbon buildup and affect fuel pump operation due to weak pulsing
​

 

[PensacolaJason]

I took the pulse limiter off today and was able to blow through it both ways without any obstruction. I did find a little piece of something inside the opening in the threads (see attached pictures). It almost looks like a gasket of sorts. Can anyone with knowledge of these things tell me if there is supposed to be anything between the pulse limiter and the crankcase, like a gasket or check valve or something that this piece could have come from?

 

[racerone]

Looks like thread sealant to me.-----Correct , you can blow through the pulse limiter both ways.------It closes when TOO MUCH air moves through it to protect the pump from high pressure.----That would crack the housing !

 

[PensacolaJason]

Looks like thread sealant to me.-----Correct , you can blow through the pulse limiter both ways.------It closes when TOO MUCH air moves through it to protect the pump from high pressure.----That would crack the housing !

Thanks for the info. How much pulse should I be expecting from that pulse tube after the limiter? I zip-tied a ballon to the end of the pulse tube and cranked the motor. It blew up the ballon a fair bit, but i just don’t know if that is enough or if the pulse is too weak and causing my fuel pump not to pump.

 

[racerone]

The displacement of your motor is given in a brochure as roughly 120 cubic inches or 30 per cylinder.-----Based on bore X stroke.----Actual displacement is of course less due to ports in the cylinder.-----Measure the size that the balloon went to and see how many cubic inches of air was displaced.----On the inlet to the pump air motor have you checked whether the check valves in that housing are working properly.----The high positive pulse is directed to one side of the air piston ,-----The slight negative pulse is directed to the other side of the air piston.----Sorry ----I can not use a cristel ball to work on your motor...