Help...dead in the water, air in fuel lines!!!

I ran a fuel tank dry by accident and have air in the lines. We have found there is no fuel going to the fuel manifold. We have tried everything. We believe the air is in the fuel lines where they go up then back down into the manifold. Fortunately we have a full forward fuel tank. Currently transferring all fuel to an aft tank and hoping the fuel level will be higher than the highest point of the fuel line.


Any ideas?

You need to prime your motor. I have a slight air leak and if I don't close my fuel valve I lose prime. Paid a guy $$ to prime my motor after doing my filters. I'm gonna rig up a priming pump this season. What's the pump looking thing in second pic above racor ?

I’m trying. I now have fuel in the manifold but i can’t get it to the engine. Little plunger pump doesn’t seem to do anything. Fuel line cracked off screw on filters to the injection pump. No fuel going to the pump.


Edit. Now I have fuel to the priming pumps. But I still can’t get fuel out of the filter housing. I’ve been pumping for a while. I hear fuel moving around and what sounds like air.

I was told to use starting fluid and that would be enough to fire motor and draw fuel into pump. I didn't want to try that. Make sure all filters are full of fuel and valve is open and just keep pumping.

Did you spin the tops off the Racors and fill them with fuel (or Diesel Kleen). I have the little plunger pumps on the secondary fuel filter fitting, and they would take forever to fill a Racor. They do feel like they’re doing nothing, and take a little while to purge all the air, even after filling the Racor.

That little plunger pump looks to have a wire coming from it. If it is 12volt and it were me I would try to get that pumping, may be even running a temporary wire and then open and bleed all the lines from the farthest point to the closest point to the engine right up to the injectors.

I now have generator running.

Racors are now full. Still can’t get fuel out the cracked lines. I’ll just keep pumping. Must be getting close

Greetings,
Mr. S. IF you have Lehmans, the arm that rides the cam lobe, inside the motor, MUST be completely off the cam lobe or the priming lever on the fuel lift pump will have little to no effect. Try a very quick bump of the starter to see if that makes any difference. May have to bump a few times...

Bump the engine over. The cam on the lift pump my be at the high lobe.

Edit: Your fast RTF.

I have fuel going out of these filters that go into the injection pump. No fuel out the lines. I’ve been pumping manually and with the electric priming pump. I honestly don’t get it

Open the vent on top of the engine mounted fuel filter. Use the electric pump in the photo to push fuel into system. It will flow through the engine mounted lift pump.

Fuel will not flow through the injection pump to injectors unless the engine is rotating, so don't expect any fuel at injector lines. Just need to get the body of the pump full, then use starter.

Greetings,
Mr. LM. Thanks. Now that you've put it in print I can show it to those nay sayers who think I'm not too swift...

No fuel out the injector line while cranking.

Ski in NC said:

Open the vent on top of the engine mounted fuel filter. Use the electric pump in the photo to push fuel into system. It will flow through the engine mounted lift pump.

Fuel will not flow through the injection pump to injectors unless the engine is rotating, so don't expect any fuel at injector lines. Just need to get the body of the pump full, then use starter.

Click to expand...

Ok did that. Got a puff of air then fuel. Now just fuel come out. Tightened it up. Still no fuel out of injector.

Do you know about the 2 bleed screws on the injector pump rather than cracking lines?

And starting with the throttle full forward and pulling back once it catches?

psneeld said:

Do you know about the 2 bleed screws on the injector pump rather than cracking lines?

And starting with the throttle full forward and pulling back once it catches?

Click to expand...

No I didn’t.

Have you shut off your threw hull to the engine? Water will fill water your water lift muffler and run back into the engine with continual cranking with no exhaust gas/pressure to push the water out. You don’t want to hydrolock your engine.

Shouldn’t the shut off Solenoid pull open while cranking?

Larry M said:

Have you shut off your threw hull to the engine? Water will fill water your water lift muffler and run back into the engine with continual cranking with no exhaust gas/pressure to push the water out. You don’t want to hydrolock your engine.

Click to expand...

I haven’t. I’ll do it now.

It takes about 75 pumps on mine to fill the secondary filters on the engine. Seems forever.

Full throttle didn’t work. I’m really curious about the shut off Solenoid

It would be a real coincidence for the stop solenoid to go bad at the same time, but I had a similar problem when the shutdown button on my port engine went bad and stuck on and would not allow the engine to start.

Comodave said:

It would be a real coincidence for the stop solenoid to go bad at the same time, but I had a similar problem when the shutdown button on my port engine went bad and stuck on and would not allow the engine to start.

Click to expand...

Neither **** off solenoids are moving when cranking.

WTF!

Ok the plungers pull when stop is pressed. I thought they worked the other way around

Ok I have cracked the line going into the injection pump. Tons of fuel going in. I have 1 injector line off and while cranking I get no fuel. Even with the electric pump on and me pumping the manual block mounted one

I can’t get these engines to fire. I have no fuel coming out of the top of the injection pump.

I truly don’t understand how this can be.

Please help, running low on beer.

Bleed screws on a Lehman 120 injection pump picture from manual:

jleonard said:

Bleed screws on a Lehman 120 injection pump picture from manual:

Click to expand...

Thank you but I have the 225 hp. No bleed screws

I would tighten everything back up and let the elect pump run for a few to pressurize lines. Be sure that your valves on fuel flow and return lines are open and in right position. Try cranking WOT with elect pump running, just a few quik 2sec bumps. If that doesn't work you might consider a shot of juice just to get the motor to run a few seconds.

There have been posts that the rack inside the injection pump sticks closed after the last shut down.....that is the only thing I can think of that with fuel going in but not coming out of the injection pump.


Someone might remember or a search might reveal the procedure for freeing that up. You may not want to mess with tha and if not, you are now reaching good mechanic territory.


Even pulling the pump off is not a beginner job unless you like adventure and document the crap out of everything and make sure you can see tming marks etc before you get started.


You might have something much more simple as it IS both engines at once....but if fuel is free to flow and the lift pumps are supplying it to the injection pumps and it doesn't come out the tops....you have a new one on me.....