Changed fuel filters...engine not start!

[Suncatcher]

I have read the other similar posts and have tried (I think) all the procedures to deal with an air block in my Yanmar 2GM.
I had installed a fuel turnoff between the tank and the primary filter (as previously advised). The fuel line in only ¼ inch so the fuel turn off is even smaller. Could this be a problem?
When cutting the fuel line to install the fuel turn off there didn't appear to be any fuel in the line? Although the motor has been working fine.
After installing the fuel filters (which was my first time ever doing so) I disconnected the fuel turn off at its lower end and installed a hose with an electric fuel pump which pumped fuel from a fuel container (as I read that the manual pump was near to useless and later I did try it for 20 minutes and gave up). Fuel did fill both the fuel filters quickly but nothing seemed to come from the fuel injectors. I reconnected the fuel turnoff and I turned the motor over but only lasted briefly. Tried again... nothing. Tried again with decompression (not turning off raw water inlet which I later read as wrong); then with compression...nothing.
Tried priming for twenty minutes using manual pump. No fuel came from the primary fuel filter nipple which earlier had fuel spilling from it when using the electric pump?

I'm thinking that my problem may be from the hose leading from the tank to the fuel turnoff. If it's not primed (and it did appear empty when installing the fuel turnoff) then it could be creating the air block. See pic.

The advise seems to be mixed about a priming bulb and it now appears tempting. But I'm out of ideas and welcome yours. So frustrating...and now with diesel odours in the boat...geez!

 

[Benny17441]

Don't see the need for having an elevated loop in the fuel line. A fuels shutoff petcock valve is usually installed at the tank fixture. If you say the filters filled up rapidly with fuel then this installation is not the problem other than when air enters the line the fuel will disappear back into the tank. The Yanmar 2GM have been notoriously difficult to bleed air out of the fuel system. Bleed the air out at the secondary filter next to the engine and then go to the high pressure pump and bleed the air there. If the fuel is good and there is adequate compression the engine should sputter and start. It may need to be ran at WOT for a few hours before all the air is cleared out. If your raw water discharge is under the waterline do not crank the engine repeatedly for any length of time as you may draw water into the exhaust system and the cylinders. Never had problems bleeding air out of a 2GM with the stock mechanical lift pump. I actually will lay a shop towel around the filter and a pad and have someone crank the engine with the compression released and I will open the bleed screw until it sputters clean fuel. At that point I close the compression release levers and attempt to start the engine which usually does. That business about installing electric fuel pumps in the diesel engine never caught my fancy. The mechanical pumps are reliable and self reliant.

 

[Claude L.-Auger]

Problem might be that there is air on top of the filter. You have 2 hex nuts on top of your primary filter. One might be a bleeding nut, the other a plunger to fill the filter. My Racor 220 has a similar set-up. If yours is like mine, the procedure is to unscrew the bleeding nut (I remove mine completely so I can see when it is full of clean fuel with no-airbubbles), then unscrew the plunger and pump it until filter is full and bleeding area also full. Push plunger back in and screw tight. Second, put bleeding nut back in. Thirdly, got to the Yanmar filter and unscrew bleeding nut (12mm) followed by activating the fuel lift pump little handle. If no fuel, decompress and manually rotate engine until you feel action on the pump lever. When no more air bubbles at the Yanmar filter, screw it back in and go to the high pressure pump. Unscrew bleeding nut and actuate pump lever until no more bubbles. Screw it back in. You can try starting the engine at that point. If it does not start, you will need to crack open the fuel line at the injectors, one at the time, and crank the engine momentarily (cut off water entry) until clean no bubble fuel show up. Once both are done, engine should start easily. Good luck

 

[HMT2]

I didn’t read anything about bleeding the air out of the system. Did you open the bleed screw on the senondary filter, and on the high preassure pump, or crack open the fuel tube at each injector? I have a fuel bulb that I use instead of your electric pump and it works great plus you don’t have to take apart the fuel line. If there is air in the system nothing will make it work until it’s out.

Here is a video, but don’t smoke like this guy. You can also have someone cranking the engine when you are bleeding the air out.

 

[Suncatcher]

Thanks for your replies. The problem, I believe, was getting the fuel from the tank to the primary filter. This section of hose is fairly long with an upward loop as seen in the pic. The manual Yanmar pump couldn't seem to handle it. So I removed the hose after this filter and attached a hose with an electric fuel pump, which lead to a jerry can, to this fuel hose. The electric pump drew fuel from the tank into the filter and through the hose leading from it. I then closed the fuel shutoff, removed the hose with electric pump and reattached the fuel hose. Then bled out air from secondary filter and injection pump. Started the motor..and Bob was my uncle again

 

[HMT2]

Good on you sir!

 

[jssailem]

@Suncatcher you solved the problem. Good on you. You are asking the fuel pump to lift the fuel over the hump in the hose. Not sure you need the hump. Can you realine the hose so if there is a lift it is a single lift not up down up. This may make it easier on your lift pump.

 

[Suncatcher]

@Suncatcher you solved the problem. Good on you. You are asking the fuel pump to lift the fuel over the hump in the hose. Not sure you need the hump. Can you realine the hose so if there is a lift it is a single lift not up down up. This may make it easier on your lift pump.

Yes, I'm considering replacing the hoses in the spring and will do exactly that. Thx.

 

[HMT2]

For what it’s worth when I change my fuel filters and need to bleed the air out of the lines I hook up a remote control starter switch to the starter so that I can crank the engine and bleed at the same time. like this one from Amazon.

CTA Tools 3012 Remote Control Starter Switch https://www.amazon.com/dp/B00FQSUUKG/ref=cm_sw_r_cp_tai_0fsKBbSA709X4

 

[Suncatcher]

Thx for the reminder. Having seen it used on YouTube videos I planned to get one. Just ordered a different brand
Performance Tool W80586 Heavy Duty Remote Starter
Now I have to find where to hook it up? Can you tell me?

 

[Ron20324]

Thx for the reminder. Having seen it used on YouTube videos I planned to get one. Just ordered a different brand
Performance Tool W80586 Heavy Duty Remote Starter
Now I have to find where to hook it up? Can you tell me?

Google.