Bleeding My Yanmar 3gm30f

[four winds]

I have a bulb inline and the manual lever on the lift pump. This works fine to get fuel to the bleeder on the secondary filter. I'm good to there.

The manual instructions doesn't mention the injector pump next. It says do the returns at the injectors, 1,2,3. Then the injector input connections, 1,2,3. I get nothing at any of these using the bulb or spinning the engine.

Seawater is closed. Decompression levers engaged.

I'm going to put an electric pump in place of the bulb. Is it ok to push fuel through my new lift pump with the electric?

Should the electric be able to push fuel through the injector pump to the returns or injectors without spinning the engine?

Difficult to access the injector pump input banjo bolt. Which has a bleeder built into the bolt head not mention in the manual instructions.

Maybe do the injector pump output lines, 1,2,3 before the returns?

Also, vapor lock maybe? Grasping at straws here.

I got one more shot at this at anchor with weak batteries. Or I'll be sailing back to the marina weather permitting soon.

Can't afford to charge the phone again so I'll be back in a while to see what you good folks say.

Oh the things I get myself into. Still beats a 9 to 5.

Thanks so much.

[Wanderlust]

I am far from a diesel expert and I searched many comments on here and elsewhere when I found the same problem with my 3GM30F.

I found the lever on the lift pump would fill the secondary filter, but would not get past the injector pump. I even tried using a fuel bulb (as you have) to pump fuel through but it didn't help.

Then somewhere I read that the injector pumps on these self prime, and the technique is to loosen one line on top of the injector pump and crank the engine. Fuel appeared immediately, and after quickly nipping up that fitting the engine fired straight away.

I tried the same technique on my second engine and it worked the same.

[roverhi]

Have never needed to bleed beyond the pump on the forward right, left side of the engine when I'm facing aft, side of the engine. What did you do that the engine needs need to bled through to the injectors?? Though it was really nice of Yanmar to put a phillips head on this screw that you can't get at with a screw driver. Fortunately the screw also has a hex head but very travel of a wrench to tighten/loosen it. Outboard of the that bleed screw is another hex head bolt. That is not the bleed screw but sure is easier to get at.

Sure am glad I've got solar panels to recharge the batteries in conditions like yours.

[sailorchic34]

The only way to bleed the injectors is to loosen the nut at each high pressure connection at each injector. From personal experience, after rebuilding an engine it took 45 minutes of messing with the engine.

You turn the raw water off and open the decompression levers so there is no load on the starter.

Then in 30 second runs, with the injector nuts cracked open. I'll put paper towels around each injector to catch the fuel.

Just because fuel comes out does not mean that the air bubbles are all gone. Generally the #3 injector (closest to front, marine engine cylinders are numbered from the prop shaft.) will be ready to run first is its the shortest line in a 3gm30.

Generally takes me 40 minutes or so getting all the air out before the thing will run. Generally chants are said, some call that cussing, but a lady never cusses, much. Sometimes praying to a deity helps.

Every minute or two, I would tighten the nuts and try starting. For me it takes a while and lots of chants and praying.. No need to mess with the return lines at all. And no, the lift pump, nor any electric pump will pump through the injectors. It takes about 2000 psig to lift the injector pin of its seat.

[four winds]

Beautiful sunny day today on the bay. First thing thing this morning a dophin jumped higher than my toe rail and fell horizontal, splashing me with water. Then resurfaced, chattered some dolphin speak and disappeared.

Then a loon came paddling by eyeing my hull. Dove and caught a fish I thought too big to swallow. Until a second loon surfaced causing the first to paddle away quickly while gulping to oversized meal.

Ten minutes later three white tail dear were frolicing in the water by shore until a single bark from a dog sent them back up the red bluff into the woods.

I figured all this surely was a sign the engine would practically bleed itself. But no such luck.

I put the Facet pump inline. Have good clean fuel to the output of the secondary filter.

The Injector pump input and three output lines are all but inaccesible on my backwards vdrive engine. At least without removing a fresh water hose and the seawater input at the exchanger.

So I loosened no.1 injector line and pumped with the Facet, the lift pump lever, and the bulb. All at once and individually. For quite some time. Stopping to crank on the engine several times. Not a drop at the injector line.

Tommorow I guess I'll remove the cooling hoses and try bleeding at the IP. Strange that the manual makes no mention of diddling with the IP at all. But then again on the very first page in the manual it says no.1 cylinder is at the flywheel end and in section 13 it says no.1 is at the timing gear end. So oh well.

BTW. SailorChic, (my role model for this lifestyle.. ...) I was asking if I could manually pump fuel through the IP, to the injectors without spinning the the engine. Not through the injectors.

The manual and commom mechanical sense, plus what you wrote earlier all suggests I can. Right now the Facet pump is running with the no.1 line loose at the injector. Has been for 20-30 minutes withot clicking off. Can't imagine where the fuel is going, but it's not in the crankcase or it would be full by now.

Tomorrow I'll remove those hoses and bleed at the IP and try again. Could it be that air in the IP can't escape, preventing fuel from entering. If so why doesn't the Facet pump kick off from reaching its regulated pressure?

Should I resort to those chants of which you speak? Not really my style but I'm willing to try.

Thanks everyone for your input.

[Cheechako]

I've found that engine starts very well with little bleeding. How much have you had apart prior to trying to start? I almost always just try bleeding at the injectors and no where else first. Make sure the fuel filters are full of diesel... your bulb or electric pump should do that pretty well. with the electric pump on just crack nuts in the lines and work your way along the injectors being last. Seems like the 3GM30's I had the biggest problem was keeping it from starting as you try to bleed!

[sailorchic34]

Originally Posted by four winds

BTW. SailorChic, (my role model for this lifestyle.. ...) I was asking if I could manually pump fuel through the IP, to the injectors without spinning the the engine. Not through the injectors.

The manual and commom mechanical sense, plus what you wrote earlier all suggests I can. Right now the Facet pump is running with the no.1 line loose at the injector. Has been for 20-30 minutes withot clicking off. Can't imagine where the fuel is going, but it's not in the crankcase or it would be full by now.

Tomorrow I'll remove those hoses and bleed at the IP and try again. Could it be that air in the IP can't escape, preventing fuel from entering. If so why doesn't the Facet pump kick off from reaching its regulated pressure?

Should I resort to those chants of which you speak? Not really my style but I'm willing to try.

Thanks everyone for your input.

Oh sorry, I was not clear. No you can't use a low pressure lift pump to pump through the Injector pump. It will not work. First the plunger really a metal pin, in each pump is got very close tolorances and will only pass fuel on a portion of its stroke. Second there is a spring loaded check valve on the discharge to each cylinder.

So in order to bleed the injector lines you have to turn over the engine... alot. Each 2 rotations moves a very small amount of fuel into the injector lines. something on the order of .2mm per 2 revs, its tiny.. This is why bleeding the $%^&* diesel (here I go chanting again) takes a while.

The lift pump and or electric fuel pump can only be used to bleed up to the injector pump, not through it.

[lonesoldier0408]

My engine fuel line goes up, then curves down to feed the injection pump. In that arch, of that line, air lock always occurs.
Clear the air, bleed the injector lines and watch her rumble.!

[four winds]

Cheechako, I replaced the line from secodary filter to IP 35 engine hours ago. It had a pin hole leak. It started right up without any bleeding that time.

The other day my lift pump failed out in the bayou. I sailed back to the marina and bought a new pump and then sailed back out to the bay.

When the pump was failing I'm pretty sure I sucked the fuel dry trying to keep it running.

So I replace the pump and I've only been able to get fuel to the secondary filter output.

SailorChic, thanks for the additional info I think I should be able to get it going tomorrow.

The manual suggests the only thing needed to get fuel all the way to the injectors is the lift lever on the lift pump. But that hasn't work for me.

[four winds]

lonesoldier, I'm going to do exactly that tomorrow.

I think a positive attitude always helps.

[SkiprJohn]

First of all I don't know your specific engine so you probably can ignore my input.

The last thing you changed was a fuel pump. That means you lost prime and have introduced air in the lines. The cylinders will not fire until all the air is out. The only way to get the air out is to loosen the nut on top the injector and spin the engine with the starter motor until you get solid (no bubbles) fuel spurting out the top of the injector. At the point you see solid fuel you have to tighten that nut so that no air can get back into that line while still spinning the engine. That cylinder should fire when there is solid fuel going into the injector. Move on to the next injector. Do the same.

Only spin the engine with the starter motor when that nut is opened and then close it before you stop spinning the engine. Make certain you have a topped off battery because even the best bled engine sometimes won't start if it is not spinning fast enough.

Good luck in your finding the cure.

kind regards,

[four winds]

I hear you John,

The wrenching and spinning thing is going to be hard to do by myself out here in the Bay. I wish I could find my remote starter button.

Battery is about dead too.

May have to sail back to the marina and the help of friends.

[laika]

Hey, bring a fresh batt out with ya next time or a jumper pack! Keep tryin!

I've gone thru literally 20+ racors on my primary in the last couple years dealing with a dirty ass fuel tank, so bleeding the 3gm is clockwork for me. Have sucked this engine dry many times.

I'm not sure what you've tried exactly, but with a primary racor the 3gm30f has three bleed plugs..one at the primary, one secondary, and one at the IP. If you do those in order you should be able to start the thing w/o fiddling with the injectors or anything past the IP at all. And it shouldn't take more than a handlful of revs to get it going again from dry.

If that's not the case, what else might have changed since you replaced the lift pump?

[rognvald]

Originally Posted by laika

Hey, bring a fresh batt out with ya next time or a jumper pack! Keep tryin!

I've gone thru literally 20+ racors on my primary in the last couple years dealing with a dirty ass fuel tank, so bleeding the 3gm is clockwork for me. Have sucked this engine dry many times.

I'm not sure what you've tried exactly, but with a primary racor the 3gm30f has three bleed plugs..one at the primary, one secondary, and one at the IP. If you do those in order you should be able to start the thing w/o fiddling with the injectors or anything past the IP at all. And it shouldn't take more than a handlful of revs to get it going again from dry.

If that's not the case, what else might have changed since you replaced the lift pump?

Four winds,
This is exactly the same procedure I use and have never had to bleed the injectors to start the engine. Also, it is very bad practice to use a ball pump on your fuel line and the practice will not pass an insurance survey. It has the potential to dislodge and/or collapse the ball causing numerous problems. Your lift pump's manual lever is sufficient to bleed the three items above. Hope you get it going! Good luck and good sailing.

[SkiprJohn]

Loosening and tightening bleed screws while pushing a starter button in the cockpit is impossible unless you've got orangutan arms that swivel in odd places. Whoever you bring aboard just needs to know how to push a starter button on command and let go the button on command. They don't need to be a sailor or a mechanic.
The best of luck to you and please let us know how it goes.
The fresh battery thing is pretty much a must.