JCB 8014 loss of power

[patrickr321]

Using my JCB 8014 today. Under load, the engine can stall despite being on maximum revs. Small rams don't affect it but it does happen when using the bigger arm rams and the tracking motors.

Any ideas on why this is happening. Hydraulic fluid level is good.

Thanks

 

[farmbrew]

Fuel filter gummed up perhaps? Primary or secondary filter?

 

[patrickr321]

Fuel filter gummed up perhaps? Primary or secondary filter?

Good thought, thanks. I'll start with that as pretty sure it's well overdue for a new filter!

 

[farmbrew]

There may be a pre filter below the fuel tank on a lift pump??? Could be blocked also.

 

[patrickr321]

There may be a pre filter below the fuel tank on a lift pump??? Could be blocked also.

Yes, can see that on the diagram in the manual. I'll take a look for it. Presume this is just a clean out job - not a replacement part.....

 

[farmbrew]

Yep

 

[dave78+]

Yep

Increased revs cause increased suction of fuel in the tank where a little bit of rag or paper can be sucked up and cause complete duel starvation.

 

[patrickr321]

Replaced the fuel filter today which had a good effect on engine power - particularly engine revs. So that obviously needed doing! However, there's still a problem in certain circumstances - in particular when tracking and pushing with the dozer. The machine can stall badly, and then recovers slowly.

 

[D-finch]

Does it have a mechanical lift pump? Or electric low pressure pump?

 

[farmbrew]

Did you clean the pre filter in the lift pump?
Also drain any sediment in the tank. Dirty or old fuel could be an issue.
Air filter might be another problem area.

 

[dave78+]

Get the injectors cleaned and the fuel pump calibrated.

 

[patrickr321]

Does it have a mechanical lift pump? Or electric low pressure pump?

Mechanical lift pump. It's a Tier 2 machine. We primed it with the lift pump and fuel ran out of the bleed screw easily.

 

[patrickr321]

Did you clean the pre filter in the lift pump?
Also drain any sediment in the tank. Dirty or old fuel could be an issue.
Air filter might be another problem area.

Don't know if there is a pre filter in the lift pump. Manual didn't point towards one on my Tier 2 machine - although there is one clearly shown in the Tier 3 machines. Will check the tank and the air filter, thanks.

 

[D-finch]

Mechanical lift pump. It's a Tier 2 machine. We primed it with the lift pump and fuel ran out of the bleed screw easily.

Have you cleaned the brass gauze inside the lift pump? Also check the valves in the lift pump. Is there a primary filter between lift pump and tank? Remove the fuel pipe on the lift pump (that comes from the tank) and blow through it. The fuel tank could possibly need a clean.

 

[patrickr321]

I took off the lift pump and didn't find a brass gauze. I'm still looking for a primary filter, and also how to remove the tank. To add to the dilemma, my cab doesn't have the gas struts to support the cab in the open position - so I need to find a safe way of supporting it without getting guillotined during the operation! Be nice to replace the gas struts, but I suppose they are not available any more. As usual, one thing leads to another!

 

[farmbrew]

Primary filter would have been the brass gauze in the lift pump but there may also be an in line filter?
Could be old contaminated fuel as previously mentioned.
Double check lines and joints for leaks, air in or fuel out?
Could set up temporary gravity fed fuel supply system to test?
Air filter???
Blocks of wood to chock cab will be way cheaper than new gas struts and possibly more reliable.

 

[patrickr321]

Primary filter would have been the brass gauze in the lift pump but there may also be an in line filter?
Could be old contaminated fuel as previously mentioned.
Double check lines and joints for leaks, air in or fuel out?
Could set up temporary gravity fed fuel supply system to test?
Air filter???
Blocks of wood to chock cab will be way cheaper than new gas struts and possibly more reliable.

Thanks. Will do some checking once I get the cab up and safe.

 

[D-finch]

I took off the lift pump and didn't find a brass gauze. I'm still looking for a primary filter, and also how to remove the tank. To add to the dilemma, my cab doesn't have the gas struts to support the cab in the open position - so I need to find a safe way of supporting it without getting guillotined during the operation! Be nice to replace the gas struts, but I suppose they are not available any more. As usual, one thing leads to another!

Did you completely strip the lift pump? 6 screws/bolts. Follow the fuel pipe from the lift pump back to the tank. I’d remove it and check it. I’ve had a fuel line collapse internally before causing a restriction of fuel. You may also come across an inline filter.

 

[D-finch]

Primary filter would have been the brass gauze in the lift pump but there may also be an in line filter?
Could be old contaminated fuel as previously mentioned.
Double check lines and joints for leaks, air in or fuel out?
Could set up temporary gravity fed fuel supply system to test?
Air filter???
Blocks of wood to chock cab will be way cheaper than new gas struts and possibly more reliable.

Excellent advice.

 

[patrickr321]

Was tempted to start a new post - but continuing here. Have seen some improvements with cleaning the lift pump filter (brass gauze) and with the new fuel filter. However, still getting loss of power, near stalling issues. So I'm removing the fuel tank and going to blow out / check the fuel lines and clean the gauze again - possibly have another fuel filter on standby. OK, so question now: how do you remove the - what looks like - clip on fuel lines without knackering them. What do I remove: the plastic connector or the metal hose clip further back? Is there a tool for the job? Picture attached. I think they are the same at the lift pump.

Thanks