odd engine stutter / bogged down

[iSailor]

I was out for a little cruise yesterday and on the way back the engine began to stutter and seemed to get bogged down. I had to put it in nuetral and up the revs to keep it from stalling.

At first I thought I had something on the prop, put the problem still persisted in neutral. After about a minute or so it seemed to "clear" itself and run normal. However, it happened again several times on the way back to the slip.

temp was fine, no visual issues around the engine, and we had plenty of fuel in it. Back at the dock I started it up again and ran the engine for a while but could not get it to re-create the problem.

Thoughts?

 

[Stu Jackson]

When was the last time you changed your fuel filters?

Have you checked the filter in the bottom of the electric fuel pump?

Have you re-routed your fuel lines so it goes: tank, primary filter, fuel pump?

Engine? M25XP?

 

[Witzend]

Does your buzzer sound when you turn your key on, but before the engine is started?

 

[iSailor]

Does your buzzer sound when you turn your key on, but before the engine is started?

It does the typical "beep, beep, beep etc....that is not what you are referring to is it?

 

[iSailor]

When was the last time you changed your fuel filters?

Have you checked the filter in the bottom of the electric fuel pump?

Have you re-routed your fuel lines so it goes: tank, primary filter, fuel pump?

Engine? M25XP?

I am going to investigate the fuel filter and drain any water.

 

[MarkZ]

If the electric fuel pump stops functioning the engine will still continue to run since there is still a slight fuel flow from gravity on the 310. But when you start getting into the higher rpm range while under load it will become sluggish from fuel starvation.

First check the electric power wire to the fuel pump, there's a good chance that it has become disconnected. The wire to mine broke at the terminal connection that attaches to the pump due to vibration. I replaced mine with a new terminal and reinforced/protected the connection from vibration by using several layers of heat shrink tubing.

 

[Witzend]

If you get the Beep when you turn on the key, than the fuel pump will draw current and is properly connected. The ground for the beeper is through the windings on the fuel pump motor. That is why when the engine starts and you are not over temp, or low oil pressure, than +12v will then be applied to the fuel pump and then the beeper stops sounding because +12 is now applied to both sides removing the ground from the beeper coil.
Nice diagnostic feature Catalina's tech is apparently unaware of as of September 2008.

This does not however mean the fuel pump is working...internally frozen, can not deliver fuel if there is a clog, or sucking air because of a leak in the system.

The engine will run in my system, gravity fed until ~5/8 of a tank @2200RPM without issue, after that it will start cutting out as you describe. The fact you are Beeping before start would led me elsewhere, but I would check the shovel connector that supplys the +12 to the fuel pump for corrosion anyway, maybe be intermittent. It is located on top of the pump.

 

[iSailor]

great info guys. I had no idea about the gravity flow. I topped up the fuel tank this spring and it just recently got down to around 3/4 or so.

Silly question, but where would one fine the fuel pump on the 310

 

[Witzend]

It is on the starboard aft quarter of the engine, just follow the fuel lines you can't miss it. Sorry I can't find a pic of it...Paul?

 

[valcour]

top left

 

[paulj]

iSailor


In 2006 I replaced my fuel pump with the one Stu mentions here.

No problems what so ever.......$35 at EFP 3 at Napa parts.





http://c34.org/bbs/index.php?action=printpage;topic=2515.0


paulj :troll:

 

[iSailor]

thanks for the info everyone. I will put this on my list to investigate.

 

[iSailor]

I replaced both fuel filters. When we were trying to purge the air from purge screw by the injectors by turing the key on, no fuel was pumping out. But i could get fuel out by using the finger pump on the fuel/water seperator. It seems that the lifter pump might not be working.

I do get the "beep,beep" when i turn the key on.

Should fuel pump out the bleed screw when the key is turned on?

Any other way to confirm that the fuel lifter pump is working?

Boat does start up and run fine in neutral.

Thanks
Matt

 

[Witzend]

No, it will not move fuel until it is started and has oil pressure and is not over temp.
You can however test the fuel pump. With the engine not running, turn the key to the spring loaded position (all the way), have someone else put an ear to the fuel pump, it should be making a clicking sound.

 

[iSailor]

wierd, my Universal manual says to "start the electric fuel pump by turning the ignition key to the ON poistion". Then to loosen the air bleed plug on the injector pump. This makes it seem like the fuel pump should pump fuel without running the engine. I am reading this right?

Also, I was sitting next to the engine and trying to adjust the bleeder screw with the co-captian at the helm turning the key and I did not hear any noise from the pump. Not sure if I was close enough to hear it though.

Where can I order an OEM style fuel pump? I would prefer to use the stock mounting brakets / points if I replace it.

thanks
matt

 

[Witzend]

Yea, it should be making a clicking sound only when you turn the key all the way to the spring loaded position like when activating the glow plugs when starting cold, and running, but of course you would not be able to hear it then because of the background noise. The manual you are reading is incorrect, at least would be for my setup. From studying the schematics, the engineers have wired it so the unit will only feed fuel when it is already running and not over temp and good oil pressure. This is all to protect the engine. If you happened to leave the key in the on position and for some other reason the beeper was not sounding, say it was defective by itself, and not reminding you to turn the key to the off position, than the fuel pump would just be running when the engine was not and that would probably be a unwanted condition.

These system are generally self bleed. I have never had to bleed mine after changing the filters. I do however fill the filters with fuel before I put them back on though.

Other pipe in here and confirm their experiences.

 

[Stu Jackson]

Newer engines have a weird wiring thing. You have to hold the key for the glow plugs and the pump runs. The it shuts off until oil pressure is made.

Read the details with the links here:

http://c34.org/bbs/index.php/topic,5078.30.html

I think it's an over complication of a simple system.

But at least you'll know what you have.

The two wiring diagrams ARE different even though they purport to show the same thing.

 

[Witzend]

This is where I meant to post it.
If you have one of the old fashion remote starter buttons, the ones you used when setting the point gap on you old car? You know, the one you used so you could get the cam at the apex on the distributor to fully open the points by turning over the engine. I guess I'm dating myself here. Well this works great as a remote switch to connect the fuel pump positive lead. Open up the panel and find a convenient +12 source for the other lead and press the button and your pump should run. Use it to check the pump, or bleed the system if you think it needs it.

 

[iSailor]

Paulj - were you able to use the stock mounting points/brackets when you installed the facet/purolator pump or did you have to drill new holes? Also, was it any easy hookup for the fuel lines and wires?

I contacted a local marine mechanice and he is 2 weeks out. I might have a go at replacing the pump myself. I did some digging and found an OEM style cube pump from Westerbreke but it was $196...

iSailor


In 2006 I replaced my fuel pump with the one Stu mentions here.

No problems what so ever.......$35 at EFP 3 at Napa parts.





http://c34.org/bbs/index.php?action=printpage;topic=2515.0


paulj :troll:

 

[paulj]

iSailor


I'm going down to the boat this morning and change the engine oil and I will take some detailed pictures........




paulj :troll: