Choking Diesel

[All U Get]

Hi all,

Just changed the fuel filter on our Perkins diesel and read an interesting comment in the maintenance manual. The manual has pages of technical measurements and critical data all important to a technician but only serves to balance the trim of our boat. In it however I read the bleeding of fuel lines and starting of the engine. We used the manual lift pump to fill and bleed the filter [three part assembly] and the fuel line to the mechanical fuel pump. Then using the engine starter to engage the mechanical pump, we bled each injector after finding the firing order on line.

The manual suggested 'taking off the air filter and choking the air intake with a piece of cardboard to reduce compression while starting'. Would that help. We didn't do it.

The final comment was 'in case you run the batteries flat, have your flares handy.' I guess that was the British humor coming out after reading 250 pages of specs.

 

[capta]

Hi all,

Just changed the fuel filter on our Perkins diesel and read an interesting comment in the maintenance manual. The manual has pages of technical measurements and critical data all important to a technician but only serves to balance the trim of our boat. In it however I read the bleeding of fuel lines and starting of the engine. We used the manual lift pump to fill and bleed the filter [three part assembly] and the fuel line to the mechanical fuel pump. Then using the engine starter to engage the mechanical pump, we bled each injector after finding the firing order on line.

The manual suggested 'taking off the air filter and choking the air intake with a piece of cardboard to reduce compression while starting'. Would that help. We didn't do it.

The final comment was 'in case you run the batteries flat, have your flares handy.' I guess that was the British humor coming out after reading 250 pages of specs.

We've changed that silly secondary for a spin on. Its a kit and super easy to do. Do you not have Racor primaries for the Perkins and genset?
I added a priming bulb like on an outboard to fill the filters and fuel lines to the injection pump on the Perkins. Then, as you said, we must bleed the fuel lines at the injectors. Never had to "choke" the engine nor has it ever taken so much starter time as to wear down the batteries.
If I weren't so lazy, I'd probably add electric fuel pumps to both engines, but so far the priming bulb has worked flawlessly.

 

[31seahorse]

Barnyard question here, so I might be on the wrong forum.

We have a 3 cylinder Perkins diesel on a Massey Ferguson 231 tractor of 1996 vintage. While driving down a steep grade pulling the brush hog the engine quit running. At the bottom of that grade the engine would not start. After saying a few choice (but non-repeatable words) I realized that although there was more than a gallon of fuel in the 6 gallon tank I had starved the engine. What I discovered upon further investigation is the fuel exits the tank from the rear left corner of the tank. The slope of the hill was enough to expose the fuel line's end and some air was sucked into the fuel lines.

Here is my question for capta and All you Get...…..Where should I consider installing the squeeze bulb? Before or after the fuel lift pump? The line to the lift pump is flexible fuel line material, and the lines beyond the lift pump are metal tubing. Capta, does your squeeze bulb pump through the lift pump on your engine?

I, too, have thought about an electric fuel pump, but I would have the same location question with that pump....before or after? The bulb would be less to fuss with. BTW on our Oday 272 had a Perkins 10hp diesel. The engine seemed to be self-bleeding. Never had a problem with air blockage. Perhaps we were just lucky.

 

[capta]

Barnyard question here, so I might be on the wrong forum.

We have a 3 cylinder Perkins diesel on a Massey Ferguson 231 tractor of 1996 vintage. While driving down a steep grade pulling the brush hog the engine quit running. At the bottom of that grade the engine would not start. After saying a few choice (but non-repeatable words) I realized that although there was more than a gallon of fuel in the 6 gallon tank I had starved the engine. What I discovered upon further investigation is the fuel exits the tank from the rear left corner of the tank. The slope of the hill was enough to expose the fuel line's end and some air was sucked into the fuel lines.

Here is my question for capta and All you Get...…..Where should I consider installing the squeeze bulb? Before or after the fuel lift pump? The line to the lift pump is flexible fuel line material, and the lines beyond the lift pump are metal tubing. Capta, does your squeeze bulb pump through the lift pump on your engine?

I, too, have thought about an electric fuel pump, but I would have the same location question with that pump....before or after? The bulb would be less to fuss with. BTW on our Oday 272 had a Perkins 10hp diesel. The engine seemed to be self-bleeding. Never had a problem with air blockage. Perhaps we were just lucky.

I installed mine above the fuel tank to keep it away from the heat of the engine room. The biggest problem with a tractor I should think is placing it where it is convenient to reach and yet be secure from brush, fence wire or whatever you might run over with the tractor.
It easily pushed the fuel through the fuel pump, but not the injection pump. However, I doubt that it could keep the engine running in the scenario you described, just make it easier to get going again.
My suggestion would be to add a second fuel line from the front of the tank. Most fuel filters have inputs for more than one fuel line on them and this might solve the problem.

 

[All U Get]

We've changed that silly secondary for a spin on. Its a kit and super easy to do. Do you not have Racor primaries for the Perkins and genset?
I added a priming bulb like on an outboard to fill the filters and fuel lines to the injection pump on the Perkins. Then, as you said, we must bleed the fuel lines at the injectors. Never had to "choke" the engine nor has it ever taken so much starter time as to wear down the batteries.
If I weren't so lazy, I'd probably add electric fuel pumps to both engines, but so far the priming bulb has worked flawlessly.

Yes on the Racors and a spin on conversion would help. We found the firing order, [1,3,4,2] on line and it worked.

Barnyard question here, so I might be on the wrong forum.

We have a 3 cylinder Perkins diesel on a Massey Ferguson 231 tractor of 1996 vintage. While driving down a steep grade pulling the brush hog the engine quit running. At the bottom of that grade the engine would not start. After saying a few choice (but non-repeatable words) I realized that although there was more than a gallon of fuel in the 6 gallon tank I had starved the engine. What I discovered upon further investigation is the fuel exits the tank from the rear left corner of the tank. The slope of the hill was enough to expose the fuel line's end and some air was sucked into the fuel lines.

Here is my question for capta and All you Get...…..Where should I consider installing the squeeze bulb? Before or after the fuel lift pump? The line to the lift pump is flexible fuel line material, and the lines beyond the lift pump are metal tubing. Capta, does your squeeze bulb pump through the lift pump on your engine?

I, too, have thought about an electric fuel pump, but I would have the same location question with that pump....before or after? The bulb would be less to fuss with. BTW on our Oday 272 had a Perkins 10hp diesel. The engine seemed to be self-bleeding. Never had a problem with air blockage. Perhaps we were just lucky.

On my 40 year old backhoe I just squirt some ether in the air filter and don't bother to prime. I get a smokey start every time.

 

[31seahorse]

Thank you for your responses! My hope was to understand the bleeding process you used to restart the engine after filter change or some other reason for air in the lines. Capta: "brush, fence wire, or whatever you might run over" It sounds like you have watched me run the tractor. All U Get: I thought about ether (that was my wife's suggestion) and I have seen a U-tube video of spraying diesel fuel into the air intake after the filter was removed. Thanks again for your ideas. You may now return to boat questions!

 

[Sailor Sue]

Would it be simpler to just keep more fuel in the tank?

 

[All U Get]

Would it be simpler to just keep more fuel in the tank?

Don’t confuse the issue with logic.

 

[kloudie1]

Blocking the intake while bleeding would make the starter motor and battery jobs easier.. but not starting for sure!They must have meant "while using the starter to bleed" ..

 

[All U Get]

Blocking the intake while bleeding would make the starter motor and battery jobs easier.. bit not starting for sure!They must have meant "while using the starter to bleed" ..

That's what we figured, choking the air during the time you're using the starter to bleed. Maybe it wouldn't wear the battery as much. When we go through the Abacos I'll ask Emma from Five Flip Flops to read it to me, she's British.

 

[Davidasailor26]

Many engines advise against cranking for too long for fear that water will back up the exhaust into the cylinders. Wonder how you'd avoid that if using the starter to bleed the fuel lines.

 

[All U Get]

Many engines advise against cranking for too long for fear that water will back up the exhaust into the cylinders. Wonder how you'd avoid that if using the starter to bleed the fuel lines.

Close the raw water intake.

 

[gettinthere]

My understanding is you never use ether on a diesel...
Installing the primer bulb outside the engine space is good but remember, they are not rated for any interior use.

 

[Don Crowther]

My understanding is you never use ether on a diesel...
Installing the primer bulb outside the engine space is good but remember, they are not rated for any interior use.

That's only if you have glow plugs. Because the glow plugs could cause a pre mature ignition when the ether hits them. And in turn blow the head gasket.

 

[All U Get]

Here's the panel on my backhoe F7500, number 3 is for ether.