CAV injector pump timing issues.

[celandine]

After a good hard run, my engine exhibits signs of being too far advanced. Ie stops on tick-over, and then appears to fire before TDC requiring starter plus domestic batteries to spin her over for re-restarting. None of the above occurs when starting from cold. I have checked that the engine is not getting tight due to over-heating.

I am questioning whether the pump is sticking in the automatic advanced mode, or whether it is generally too far advanced (but only firing early when hot)
At present it is on the factory timing marks. The engine is a Watermota Seapanther 33 yrs old.

Any ideas?

 

[dunmor]

may not be pump, injectors could be leaking.

 

[lynall]

Is that the old type cav pump that has timing marks under the cover plate on the pump itself?


Lynall

 

[celandine]

Is that the old type cav pump that has timing marks under the cover plate on the pump itself?


Lynall

I am not sure if it is the old type. There is a visible timing mark on the mounting flange that lines up with a mark on the engine body.

 

[Bilgediver]

After a good hard run, my engine exhibits signs of being too far advanced. Ie stops on tick-over, and then appears to fire before TDC requiring starter plus domestic batteries to spin her over for re-restarting. None of the above occurs when starting from cold. I have checked that the engine is not getting tight due to over-heating.

I am questioning whether the pump is sticking in the automatic advanced mode, or whether it is generally too far advanced (but only firing early when hot)
At present it is on the factory timing marks. The engine is a Watermota Seapanther 33 yrs old.

Any ideas?

Is it this one? Is the antibacklash thingy there if supposed to be?

http://www.bluemoment.com/manuals/Lucas CAV DPA injection pump instruction book.pdf

 

[savageseadog]

Have you swapped any injector lines? If you have, it is sometimes possible to transpose the lines.

 

[celandine]

Is it this one? Is the antibacklash thingy there if supposed to be?

http://www.bluemoment.com/manuals/Lucas CAV DPA injection pump instruction book.pdf

Yes. It appears to be the one illustrated.

 

[celandine]

Have you swapped any injector lines? If you have, it is sometimes possible to transpose the lines.

If you mean have I possibly re-connected injector pipes wrongly, then, no. I haven't dared touch it. Hence my original question.

 

[saxonpirate]

I'm just wondering if this is fuel starvation (doesn't need much) affecting injection pump timing or water in the fuel. When she's running have you looked at your exhaust and the smoke (if any) colour when starting when cold and then hot. Crack off your injector pipes when its hot and see if you are getting a good even supply of fuel to all injectors, if not gently crack off the bleed screws on the side of the pump and see if you have fuel there. What sort of leak back system have you from your injectors, make sure its not restricted or blocked. Its many years since I worked with DPA pumps in plant engineering, but one thing that is burned in my memory about them is their extreme sensitivity to any moisture/dirt in the fuel.

 

[celandine]

I'm just wondering if this is fuel starvation (doesn't need much) affecting injection pump timing or water in the fuel. When she's running have you looked at your exhaust and the smoke (if any) colour when starting when cold and then hot. Crack off your injector pipes when its hot and see if you are getting a good even supply of fuel to all injectors, if not gently crack off the bleed screws on the side of the pump and see if you have fuel there. What sort of leak back system have you from your injectors, make sure its not restricted or blocked. Its many years since I worked with DPA pumps in plant engineering, but one thing that is burned in my memory about them is their extreme sensitivity to any moisture/dirt in the fuel.

I have checked for fuel contamination etc. Is it possible to have the problems you mention and still hav good starting from cold and with even running at higher revs? I only have problems when returning to tick-over with a well warmed engine.

 

[dunmor]

I have checked for fuel contamination etc. Is it possible to have the problems you mention and still hav good starting from cold and with even running at higher revs? I only have problems when returning to tick-over with a well warmed engine.

if injectors are leaking it will start well because it is rich, when warm it is over fueling which will give problems!!!!

 

[saxonpirate]

if injectors are leaking it will start well because it is rich, when warm it is over fueling which will give problems!!!!

To add to that, I'll repeat what I said in my earlier comment... check the smoke! An awful lot of diesel engine problems can be diagnosed from what's coming out of the exhaust. Consequently, if there is no smoke of any colour you can start to dismiss a few things from your diagnosis list. Start simple with diagnostics and smoke colour checking is essential, as is clean fuel and good compression. One thing I wanted to ask the OP is this... when you say it won't idle after a run and its hot, if you gradually decrease the revs down to idle does it stop abruptly or get very lumpy for a few seconds before stopping as if it were not firing on all cylinders?

 

[ukmctc]

I had a similar problem, take the pump off along with your injectors and send them along to Colchester Diesel, excellent service and cheap too, it'll all be returned like new, refit and see what happens, if all else fails you won't need to worry about those bits for another 30 years.
My pump had an air leak in the top intake run control. Its only held in with aroldite (from manufacture).