Fuel pump issue

[Kaltoft]

Hi

I hope someone with knowledge of diesel fuel pumps are able to help me a bit.

My Bobcat 2400 articulated loader has issues with its fuel supply

Motor: Perkins 4.236
Fuel Pump: Lucas CAV

The problem was a broken fuel pump, that I have now repaired with new parts. However, I have issues starting the engine. With the repaired pump I am now able to get fuel to all injectors, however the engine does not fire up at all. If I use starting fluid the motor fires as expected. It ran fine before the fuel pump died.
The problem with the fuel pump was accumulated dirt blocking the rotation of the pump head, and causing the main axle in the pump head to break from the force of the starter motor.

Could the fact that the engine was allowed to rotate with the broken pump with a stationary pump-head have caused the engine and pump to be out of time?

 

[CoyPatton]

Hi

I hope someone with knowledge of diesel fuel pumps are able to help me a bit.

My Bobcat 2400 articulated loader has issues with its fuel supply

Motor: Perkins 4.236
Fuel Pump: Lucas CAV

The problem was a broken fuel pump, that I have now repaired with new parts. However, I have issues starting the engine. With the repaired pump I am now able to get fuel to all injectors, however the engine does not fire up at all. If I use starting fluid the motor fires as expected. It ran fine before the fuel pump died.
The problem with the fuel pump was accumulated dirt blocking the rotation of the pump head, and causing the main axle in the pump head to break from the force of the starter motor.

Could the fact that the engine was allowed to rotate with the broken pump with a stationary pump-head have caused the engine and pump to be out of time?

Yes that is a possibility. Your injector pump must be timed to the engine. When out of time, it delivers fuel to the cylinder at the wrong time. Your service manual should describe the timing process for the pump.

 

[Kaltoft]

Yes that is a possibility. Your injector pump must be timed to the engine. When out of time, it delivers fuel to the cylinder at the wrong time. Your service manual should describe the timing process for the pump.

I understand that timing is critical. I just dont see how the pump could be installed to be out of time.
When refurbishing the pump I noticed that all parts are designed to only be able to go back in one orientation, and the pump itself is only able to mount to the engine in one orientation due to a notch on the pump that meshes with the fuel pump gear on the engine. The pump has timing marks that are aligned with timing marks on the engine body.

 

[CoyPatton]

I understand that timing is critical. I just dont see how the pump could be installed to be out of time.
When refurbishing the pump I noticed that all parts are designed to only be able to go back in one orientation, and the pump itself is only able to mount to the engine in one orientation due to a notch on the pump that meshes with the fuel pump gear on the engine. The pump has timing marks that are aligned with timing marks on the engine body.

Could it be 180 out if time?

 

[Kaltoft]

Could it be 180 out if time?

The symptoms certainly seem to indicate that, but I just don't see how it could be assembled to be 180 degrees out of time


Engine fuel pump timing gear


Pump notch


Timing marks engine/pump

 

[rowellc]

Hi

I hope someone with knowledge of diesel fuel pumps are able to help me a bit.

My Bobcat 2400 articulated loader has issues with its fuel supply

Motor: Perkins 4.236
Fuel Pump: Lucas CAV

The problem was a broken fuel pump, that I have now repaired with new parts. However, I have issues starting the engine. With the repaired pump I am now able to get fuel to all injectors, however the engine does not fire up at all. If I use starting fluid the motor fires as expected. It ran fine before the fuel pump died.
The problem with the fuel pump was accumulated dirt blocking the rotation of the pump head, and causing the main axle in the pump head to break from the force of the starter motor.

Could the fact that the engine was allowed to rotate with the broken pump with a stationary pump-head have caused the engine and pump to be out of time?

You probably have air in the lines. You will have to drain the fuel injectors till there is no more air. You will know when the fuel injectors stop dribbling fuel and start squirting again
I just had this issue with my 8010 diesel New Holland. My problem is my fuel pump comes on by itself when the engine is turned off.

 

[Kaltoft]

You probably have air in the lines. You will have to drain the fuel injectors till there is no more air. You will know when the fuel injectors stop dribbling fuel and start squirting again
I just had this issue with my 8010 diesel New Holland. My problem is my fuel pump comes on by itself when the engine is turned off.

That has been my hope so far, however I have now drained a large completely charged 170Ah battery twice trying to bleed the fuel system and no improvement yet, never a single ignition despite fuel coming out at the injectors when the lines are loosened
and white smoke coming from the exhaust.

 

[Loaderman22]

Where's thepumpguysc? he typically knows these things off the top of his head??

 

[Tinhack]

The symptoms certainly seem to indicate that, but I just don't see how it could be assembled to be 180 degrees out of time

The cam that drives the pump could be 180 degrees out or on intake/exhaust on a different cylinder than you expect. You said the engine turned without turning the pump. The cam turns one time for every two rotations of the engine. You need to follow the procedure for timing the pump for that engine. You can NOT just install the pump to align the pin after the engine has turned and not the pump. You could be injecting diesel in a different cylinder on the exhaust stroke.

You need to know where the engine is in it's timing and match the injector pump to that.

 

[CoyPatton]

The cam that drives the pump could be 180 degrees out or compressing on a different cylinder than you expect. You said the engine turned without turning the pump. The cam turns one time for every two rotations of the engine. You need to follow the procedure for timing the pump for that engine. You can NOT just install the pump to align the pin after the engine has turned and not the pump. You could be injecting diesel in a different cylinder on the exhaust stroke.

You need to know where the engine is in it's timing and match the injector pump to that.

There should be detailed timing process for both the engine and the injector pump in the service manual. Failure to follow these procedures, means you are shooting in the dark, with a blind fold on after having bern spun until your brain does not know up from right, right from down or down from left.

In simple terms, the pump must be timed so it injects fuel for cylinder 1 when cylinder 1 is on the intake stroke. To try this without closely following the timing procedure is near possible.

 

[WranglerX]

Seems to me the since there is only one way pump slot will fit on PIN of cam you are either in time or 180 out....

Dale

 

[WranglerX]

Seems to me the since there is only one way pump slot will fit on PIN of cam you are either in time or 180 out....

Dale

 

[Tinhack]

Seems to me the since there is only one way pump slot will fit on PIN of cam you are either in time or 180 out....

Dale

And that would be for which cylinder? And which injector will get the juice? That can't be determined by what is shown in the photos. You didn't read the whole problem.

 

[Kaltoft]

The cam that drives the pump could be 180 degrees out or on intake/exhaust on a different cylinder than you expect. You said the engine turned without turning the pump. The cam turns one time for every two rotations of the engine. You need to follow the procedure for timing the pump for that engine. You can NOT just install the pump to align the pin after the engine has turned and not the pump. You could be injecting diesel in a different cylinder on the exhaust stroke.

You need to know where the engine is in it's timing and match the injector pump to that.

View attachment 678634

I have attached an image of the Perkins 4.236 engine with the timing cover removed, sourced from YouTube - the cam gear being the small one in the bottom and the fuel pump gear top right. Here you can see that the cam gear is half the size of the fuel pump gear - so for every two revolutions of the engine/cam gear the fuel pump gear rotates one time. So I do not believe your statement to be true for this engine / fuel pump situation.
I searched through the manual for the engine, and the only way it mentions timing of the fuel pump, is by adjusting the pump in the slotted mounting holes from my last photo in post #5 which only allows a few degrees of timing adjustment.

With this engine / pump setup, you should be able to just randomly mount the engine and expect it to be roughly in time, from what I have been able to research.

In fact, the only way I can make sense of what is happening, is if the fuel pump gear skipped several teeth when the fuel pump was stuck, before breaking the pump head axle in the fuel pump, and thereby making the gear be out of time. Does that sound plausible?

 

[CoyPatton]

View attachment 678634

I have attached an image of the Perkins 4.236 engine with the timing cover removed, sourced from YouTube - the cam gear being the small one in the bottom and the fuel pump gear top right. Here you can see that the cam gear is half the size of the fuel pump gear - so for every two revolutions of the engine/cam gear the fuel pump gear rotates one time. So I do not believe your statement to be true for this engine / fuel pump situation.
I searched through the manual for the engine, and the only way it mentions timing of the fuel pump, is by adjusting the pump in the slotted mounting holes from my last photo in post #5 which only allows a few degrees of timing adjustment.

With this engine / pump setup, you should be able to just randomly mount the engine and expect it to be roughly in time, from what I have been able to research.

In fact, the only way I can make sense of what is happening, is if the fuel pump gear skipped several teeth when the fuel pump was stuck, before breaking the pump head axle in the fuel pump, and thereby making the gear be out of time. Does that sound plausible?

Assuming your assumptions about mounting the pump in any random order and it would be in time, would imply that the injector pump is continuously sending fuel to every cylinder
This would then imply that only 1/4 of the fuel sent to the injectors actually provides any power, and lots of raw fuel (3/4 of what the pump pumps)

Bottom line is this is stinking thinking and the result is an engine that does not run!

Fact, injection pumps must be timed. Will be timed from a reputable repair shop.
Fact the engine must be timed prior to the injector pump being installed.

Think old style cam driven distributor gas burners. 1 tooth off on the distributor gear to the cam shaft gear and the vehicle ran like crap, it was close but far enough out that you quickly knew it.

 

[Kaltoft]

Assuming your assumptions about mounting the pump in any random order and it would be in time, would imply that the injector pump is continuously sending fuel to every cylinder
This would then imply that only 1/4 of the fuel sent to the injectors actually provides any power, and lots of raw fuel (3/4 of what the pump pumps)

Bottom line is this is stinking thinking and the result is an engine that does not run!

Fact, injection pumps must be timed. Will be timed from a reputable repair shop.
Fact the engine must be timed prior to the injector pump being installed.

Think old style cam driven distributor gas burners. 1 tooth off on the distributor gear to the cam shaft gear and the vehicle ran like crap, it was close but far enough out that you quickly knew it.

Ok, it appears I have the wrong idea of how this is supposed to work. I just happened to locate a youtube video of this engine being rebuilt, which also explains that if you turn the engine over without the fuel pump mounted "you are screwed"
3.9 Perkins 4-cyl Final Assembly | Massey Ferguson 270 [EP4] - YouTube

So I guess I have to re-set the fuel pump timing to the engine.
According to the manual of the engine - that is done by:
- position the crankshaft so that no.1 piston is at tdc on compression stroke
- in the inspection window on the fuel pump, letter C should be aligned with circlip in the fuel pump

And if they are not aligned, I guess I will have to remove the timing case cover, and reposition the idler gear and fuel pump gear until everything lines up.
Does that sound reasonable ?

 

[Kaltoft]

Ok, it appears I have the wrong idea of how this is supposed to work. I just happened to locate a youtube video of this engine being rebuilt, which also explains that if you turn the engine over without the fuel pump mounted "you are screwed"
3.9 Perkins 4-cyl Final Assembly | Massey Ferguson 270 [EP4] - YouTube

So I guess I have to re-set the fuel pump timing to the engine.
According to the manual of the engine - that is done by:
- position the crankshaft so that no.1 piston is at tdc on compression stroke
- in the inspection window on the fuel pump, letter C should be aligned with circlip in the fuel pump

And if they are not aligned, I guess I will have to remove the timing case cover, and reposition the idler gear and fuel pump gear until everything lines up.
Does that sound reasonable ?

Ok, I just saw the video again, and I think I misunderstood it.

In the video it is mentioned that if you turn the engine over with the injection pump removed - "you are screwed"

I never turned my engine over without the injection pump installed - I turned the engine over with a injection pump that was broken internally. So I do still not see how my timing could be changed - the gears in the case are in the same relative positions as they have alway been - assuming the blocked pump did not make one of the gears skip.

Assuming the injection pump gear has not skipped - as I see it, it should still be in time with the engine when mounted, as the pump can only be mounted in one orientation due to the notch and the alignment marks on the pump/engine.

What am I missing ?

 

[Kaltoft]

The cam that drives the pump could be 180 degrees out or on intake/exhaust on a different cylinder than you expect. You said the engine turned without turning the pump. The cam turns one time for every two rotations of the engine. You need to follow the procedure for timing the pump for that engine. You can NOT just install the pump to align the pin after the engine has turned and not the pump. You could be injecting diesel in a different cylinder on the exhaust stroke.

You need to know where the engine is in it's timing and match the injector pump to that.

I might not have explained myself well enough in my first post.
The engine never turned without the pump turning. The engine turned with a pump that was broken internally, so the timing should not be affected, as the timing is decided by the fuel pump timing gear.
One complete rotation of the injection pump delivers four injections of fuel, so if the pump timing gear has not skipped, it will still be in phase with the injection pump when installed again, as it only has one position to install in due to the alignment pin.

Please correct me if i get this wrong.

 

[Tinhack]

I guess you still haven't explained well enough. :laughing: What, exactly, does "The engine turned with a pump that was broken internally..." mean? To me, that means the engine was turning and the pump wasn't.

If the pump shaft was broken, as you indicated, the timing for the pump is off and can't possibly match the engine timing except by a miracle.

Which cylinder is on the intake stroke right now? Which injector would be fed right now? I bet you can't answer those two questions.

 

[Kaltoft]

I guess you still haven't explained well enough. :laughing: What, exactly, does "The engine turned with a pump that was broken internally..." mean? To me, that means the engine was turning and the pump wasn't.

If the pump shaft was broken, as you indicated, the timing for the pump is off and can't possibly match the engine timing except by a miracle.

Which cylinder is on the intake stroke right now? Which injector would be fed right now? I bet you can't answer those two questions.

They say a picture is worth a thousand words - this is the broken pump head from the pump - it has been replaced with a new pump head. So most of the broken pump was still rotating, up to the broken axle, and more importantly, the pump gear, that is in time with the engine was still rotating.

There are no timing adjustments on this type of pump - when assembling, all gears have one double tooth, so they only go on one way, so there is no way to assemble the pump "out of time".

Here is a video of someone replacing a pump of the same model as mine: Replacing a Ford 3000 Injection Pump - YouTube as you can see in the video, no adjustment of timing on a replacement pump is necessary.

The engine timing is controlled by the timing gear that hopefully is still timed the same way with the engine. So no, I cannot answer your two questions, and i believe that I do not have to be able to do so.