Correct place to bleed the fuel rail?

[Bob Quinn]

Is this the correct place to bleed the fuel rail / system after changing filters?
Thank you!

 

[cww]

Detroits are self-bleeding. Just fill up the filters with diesel before you screw them back on and then start it up. It will crank longer than usual and may have some white smoke initially but it will clear the air out quickly and run fine. No need to crack fuel lines or anything like that on a detroit.

 

[Bob Quinn]

Detroits are self-bleeding. Just fill up the filters with diesel before you screw them back on and then start it up. It will crank longer than usual and may have some white smoke initially but it will clear the air out quickly and run fine. No need to crack fuel lines or anything like that on a detroit.

I cranked it a LOT over the course of a couple hours. I would let it sit for a while and try again about every 15 minutes.

I filled the canister filters to overflowing before screwing them back in place and the large one with the glass bowl I filled from the top port until full.

Maybe I have a different problem?

The boat stalled on the way to get a pump out at my marina and restarted a couple times but then kept stalling and finally wouldn't start. I was stuck at the pump out dock for hours before getting towed back to my slip.

Could I have a bad fuel pump?

 

[Captain Ralph]

Do you have any vacuum gauges on the filters?
Any low pressure readings when / after trying to start the engines?
Lots of fuel in the tanks? Really?
All tank and filter valves in correct positions? Really?

Our ole Bertram has a priming pump also. Think I have used it once for the main engines in the 18 years of owner ship.

However, Have used it often in troubleshooting gen-set issues.

 

[scottinsydney]

You could attach a 12 v or manual fuel pump hose to the IN side of the fuel filter to assist fuel up to the injectors.

Also make sure that the return line has a section of hose higher than the motor so that fuel does not siphon out of the motor and back to the tank.

 

[Captain Ralph]

Could I have a bad fuel pump?

Back to the OP, star gear fuel pumps don't move air well when dry.
Either out of fuel or high restrictions. There is a lip seal on the drive shaft. It usually leaks a drop or two when not running is the sign if it is going bad.

If you have a cartridge secondary and it is full of fuel, open the Racor top and try to just draw that small amount of fuel thru the secondary. When the engine catches, turn it off, refill the Racor and install the top. Ensure that lil O ring if in good shape and wet with fuel when tightening down the T handle.

Any work done recently on the engines? Hose or fitting bumped maybe?

Where are you hiding your ship? I'm in FL 32189 if you need a 3rd hand.

 

[Pascal]

Save yourself the agravation and add a priming pump like a Walbro or any small electric pump. Well worth it since Detroits don’t have any built in priming pump

Yes you can rely on the gear pump and cranking but not worth stressing your starter and batteries

 

[zigzag930]

The way I was taught was to remove the "return line" from the engine (wherever it might be attached) and hook up a vacuum pump (think oil extractor) to the engine. Create the vacuum by pumping the extractor pump a few times which should pull fuel through everything (filters, engine, rails, etc) and then start the engine once fuel is pulling through. This should work and is a pretty easy way to go. The extractor can be used for dozens of other projects in the engine room etc.

Don't forget to turn the engine off once it starts or you will pump a whole lot of diesel into that extractor pump canister.

Had to do this 2x with my DD 471's when I first bought the boat and had bad fuel. No more issues.

 

[Captain Ralph]

The way I was taught was to remove the "return line" from the engine (wherever it might be attached) and hook up a vacuum pump (think oil extractor) to the engine. Create the vacuum by pumping the extractor pump a few times which should pull fuel through everything (filters, engine, rails, etc) and then start the engine once fuel is pulling through. This should work and is a pretty easy way to go. The extractor can be used for dozens of other projects in the engine room etc.

Don't forget to turn the engine off once it starts or you will pump a whole lot of diesel into that extractor pump canister.

Had to do this 2x with my DD 471's when I first bought the boat and had bad fuel. No more issues.

I do like this idea. Further, a diverting Y valve could be permanently installed.

Before we go to much further with all these engineering ideas, we need to get the O P running easily. If I knew he was close, I could help and offer a third hand. Get him running and fix what the issue is.
Remember, no issues, then he was running poorly just before it died,,,, dead.. At the poo pump out.

 

[Bob Quinn]

Got it!

o.k. so I couldn't readily find any of the hand pumps suggested so out of desperation I got what was available at the local O'Reilly's auto parts.
They had a small electric diesel fuel pump by Edelbrock, 6 foot of 5/16 i.d. fuel line, some battery charger electrical clips to hook to the battery and 8 foot of lamp cord. Oh and a brass 1/4 npt to 1/8 npt fitting to connect to an open port on the lower can style filter housing, screwed into a fuel shot off valve, and a barb fitting for the other side of that. put the suction end of the pump in a 2 gallon can of fuel oil and ran the pump until fuel came out into a bucket. Once I got fuel through the little electric pump I plugged the output hose onto the brass shut off valve I screwed into the can filter.
I cracked free the fuel line on the output side of then motors fuel pump where I posted the picture above. Ran the pump for about 30 seconds and fuel started to dribble out with some air. Ran it maybe another 30 seconds and it pushed out maybe a few tablespoons of fuel oil onto the rag I put under it. Tightened the fuel line, turned off the little brass fuel shut off valve now installed on the can fuel filter. Hit the start button and presto! Runs like a top! The setup cost about $130 bucks but $80 of that was the little electric pump. Thank you all for your help!

Also now if I have to do this again the fuel shut off valve is in place and the pump can just plug into it with the hose barb.

 

[SKYCHENEY]

Glad to hear you got it going.

 

[Bob Quinn]

Thank you, me too! I'm going to try to take some pictures later.
The biggest battle in all this was figuring out where to hook up and what lines are what.
Maybe some pictures will help some other newbee like me down the road!

Thank you for the help!

 

[Pascal]

Years ago I lost prime on my starboard 8V71N. I ran some Fuel hose from the generator electric pump to the DD and came home like that

 

[cww]

Years ago I lost prime on my starboard 8V71N. I ran some Fuel hose from the generator electric pump to the DD and came home like that

That's some Macguyver right there!

 

[Pascal]

That's some Macguyver right there!

It was!

When i repowered I let my “installer” talked me into not adding priming pumps since the C series have manual priming pumps. I regretted it and while I only had one priming issue after a filter change, i regret not having installed priming pump and will soon.

They can save the day when in a bind. Actually, back in March I had a failing fuel pump on a 45KW Onan on the 116 i run while on a month long trip in the Exumas, always on the hook. I was able to run the gen by leaving the priming pump on. We have two gens but it was comforting to know that one would run on the priming pump

 

[Avenger]

Years ago I lost prime on my starboard 8V71N. I ran some Fuel hose from the generator electric pump to the DD and came home like that

Impressive fuel pump for a generator.

 

[Bob Quinn]

Pic's of diesel fuel line bleeding setup

Left pic is the Edelbrock pump setup I should have also installed a switch near the pump but made do with just cutting the wire and holding the ends together by hand.
Right two pictures are where I added fittings and a shut off valve to connect the outlet end of the pump to with a rubber fuel line hose.

 

[Bob Quinn]

Outlet hose connection point for bleeding fuel pump / Line

This is where I pluged in the fuel line from the outlet side of the Edelbrock pump.
No need for a clamp it's low pressure like 5 to 7 psi I think the spec's were.
Also note the shut off valve. I put in the shut off valve for two reasons.
First, so that when the system was primed, I could just shut off the valve and unplug the hose with out risk of fuel draining back out of the system and also so I had an easy plug in point in case this happens again. I would hate to be on the water somewhere with a dead motor and have to scramble for a way to do this.
Make sure to turn off the fuel valves to the tank so your not just pumping fuel back to the tanks and all the pump pressure is pushing fuel forward into the system.

A couple thoughts... The electric pump is probably overkill. Previous responses to this post show a hand pump made for priming systems that would be easier to facilitate. I only used the electric pump because this is what was readily available at the auto parts store. I went to several auto parts store and they all seemed to have these on the accessory rack.

Second thought is this: Many people say the Detroit diesels are self priming. I am not arguing that point, but others have said they have had to do the same thing, and it may be due to a week fuel pump. The other possibility I see is that they may self prime "if" there is fuel in the pump. Maybe not so self priming if fuel has drained from the pump. Or I just have a worn out pump.
Either way, this did the trick.

Search tags: fuel pump prime, top rail prime, fuel pump bleed, top rail bleed, fuel system bleed, air in fuel line, won't run after filter change, diesel fuel filter change, diesel filter change, No fuel etc. <-- Just to help people find this post.

No this doesn't bleed the fuel rail, just gets fuel to the pump.

Thank you all for your help!

 

[Captain Ralph]

Thank you, me too! I'm going to try to take some pictures later.
The biggest battle in all this was figuring out where to hook up and what lines are what.
Maybe some pictures will help some other newbee like me down the road!

Thank you for the help!

Glad you are running.
But I'm still wondering, What caused the original rough running and cut-off when you went to the pump-out dock?

 

[Bob Quinn]

Glad you are running.
But I'm still wondering, What caused the original rough running and cut-off when you went to the pump-out dock?

Well ironic you ask, because now it did it again!
Ran the motors about 10 minutes Saturday night just for a show and tell for a friend. Started great, ran great. Sunday at 11 am again had the same problem re-occur. Motor wouldn't start again.
Got the priming rig out, and then motor ran fine for several hours.

So I must have a leak somewhere allowing the fuel to drain out of the pump?

I haven't seen any fuel dripping anywhere but I suppose it could also be draining into the tank.
I would think though that if there was a leak or a pin hole somewhere past the pump that there would be evidence of fuel leaking somewhere on the motor? Or could it be something like an injector that somehow doesn't close all the way? I don't know, it's becoming more of a mystery!