BMC 1.5 - Pump control anomaly.

[BARKERSLEY]

I have just got my BMC 1.5 diesel going after a ten year wait in the workshop. The head has been overhauled and runs very well, except -

The 'control' lever is ineffective and the engine is 'controlled' by using the engine stop lever. Revs range from excessive to nil by using the lever and there is no effect with the use of the 'control' lever when running at low or high revs. It would almost appear back to front except that the 'control' lever does nothing.

Any ideas?

 

[vyv_cox]

I have a workshop manual for the 1.5 and 2.5 litre engines. Can send you a copy if you PM me your email address.

 

[BARKERSLEY]

Thanks but I have a manual. I read the blurb and examined the exploded views but still can't understand why I have the problem. It would seem mechanically impossible for the cut off to control the revs when it's function is to shut off fuel. And the control lever does nothing. I wonder if my pump is a modification combining control and shut off, however it looks the same as the one I have in my narrowboat currently, and that works as standard.

Thanks anyway.

 

[Bilgediver]

Thanks but I have a manual. I read the blurb and examined the exploded views but still can't understand why I have the problem. It would seem mechanically impossible for the cut off to control the revs when it's function is to shut off fuel. And the control lever does nothing. I wonder if my pump is a modification combining control and shut off, however it looks the same as the one I have in my narrowboat currently, and that works as standard.

Thanks anyway.

I suspect there are internal problems with the governor in your fuel pump and it might benefit a visit to the local fuel injection specialist for a service.

 

[BARKERSLEY]

Hi. Do you think it is possible to 'control' the revs by using the cut off?

 

[vyv_cox]

I have not had my BMC 2.2 long enough to get to grips with the engine very much but I do know that the speed control is on the port side at the inlet manifold, with a butterfly almost like a carburettor on a petrol engine. The stop control is where your photo shows. I may be able to take some pics next week.

 

[TQA]

You have a CAV rotary pump with the hydraulic governor. The metering valve inside the governor, which is the bit you have photographed sticking out the side of the pump, has stuck in the full fuel position. This was a common problem with engines not run for a while.

You can try tapping with a hammer to see if it frees off but it is likely to be a strip down job. Quite simple but it must be done in a scrupulously clean work area and all items stored in a bath of parrafin or diesel.

The canal boys still use this engine so might be able to tell you who can service the pump.

 

[Jcorstorphine]

I had same problem on my old BMC 1.5 after it had not run for 5 years. It was the internal rack or governor which had stuck in full speed position. Took the pump out and had it cleaned and reset at the (then) local CAV Lucas service centre.

Just be careful that you mark the timing of the pump and do not lift out the short drive shaft which connects to the camshaft. I did and the shaft ended up in the sump.

 

[BARKERSLEY]

You have a CAV rotary pump with the hydraulic governor. The metering valve inside the governor, which is the bit you have photographed sticking out the side of the pump, has stuck in the full fuel position. This was a common problem with engines not run for a while.

You can try tapping with a hammer to see if it frees off but it is likely to be a strip down job. Quite simple but it must be done in a scrupulously clean work area and all items stored in a bath of parrafin or diesel.

The canal boys still use this engine so might be able to tell you who can service the pump.

Yes, this engine is still [probably] the most common engine on the canals, at least in boats of a certain age. Thanks for your suggestion and I will investigate what you think might be the problem. Judging from the exploded drawing the top, control, section is removable and should facilitate the access to the part that is stuck. If all else fails I can use the pump that is currently on the smoker in my boat when I get round to changing them. Many thanks.

 

[BARKERSLEY]

I had same problem on my old BMC 1.5 after it had not run for 5 years. It was the internal rack or governor which had stuck in full speed position. Took the pump out and had it cleaned and reset at the (then) local CAV Lucas service centre.

Just be careful that you mark the timing of the pump and do not lift out the short drive shaft which connects to the camshaft. I did and the shaft ended up in the sump.

Thanks for your suggestion, this is looking like a possible and I will investigate what you think might be the problem. Judging from the exploded drawing the top, control, section is removable and should facilitate the access to the part that is stuck without removing the whole pump. Many thanks.

 

[BARKERSLEY]

You have a CAV rotary pump with the hydraulic governor. The metering valve inside the governor, which is the bit you have photographed sticking out the side of the pump, has stuck in the full fuel position. This was a common problem with engines not run for a while.

You can try tapping with a hammer to see if it frees off but it is likely to be a strip down job. Quite simple but it must be done in a scrupulously clean work area and all items stored in a bath of parrafin or diesel.

The canal boys still use this engine so might be able to tell you who can service the pump.

FIXED! Thanks for your help. I removed the top 'governor' section then worked out how it was intended to work - actually quite primitive. Both control and shut off use a cam affair to lower or stop a spindle which meters fuel availability. The 'pistol' on the spindle had stuck as you suggested making the control cam ineffectual and relying on the shut off cam to raise the spindle alone. Once freed and checked and understood the cams purpose I was able to ensure it would work. A simpler job than I had expected considering the importance of the pump and it's function. Once again thanks.

 

[BARKERSLEY]

I had same problem on my old BMC 1.5 after it had not run for 5 years. It was the internal rack or governor which had stuck in full speed position. Took the pump out and had it cleaned and reset at the (then) local CAV Lucas service centre.

Just be careful that you mark the timing of the pump and do not lift out the short drive shaft which connects to the camshaft. I did and the shaft ended up in the sump.

FIXED! Thanks for your help. I removed the top 'governor' section without having to move the pump itself, then worked out how it was intended to work - actually quite primitive. Both control and shut off use a cam affair to lower or stop a spindle which meters fuel availability.My manual shows a 'ratchet' function to raise a more substantial spindle than my one. The 'pistol' on the spindle had stuck as you suggested making the control cam ineffectual and relying on the shut off cam to raise the spindle alone. Once freed and checked and understood the cams purpose I was able to ensure it would work. A simpler job than I had expected considering the importance of the pump and it's function. I imagine that because my version is prone to this problem, the more pro-active ratchet system was introduced. Once again thanks.