941B Won't start

dpendzic · Aug 22, 2017

I left the throttle in the stop position since last winter, when I pull back on it doesn't feel the same, like no detentes, the fuel pressure goes eight up into the green range. I assume something is sticking in the injection pump.
Is anyone familiar with Cat sleeve metering injection pumps?
Thanks

AJ. · Aug 23, 2017

That's a common problem with that pump,the rack is stuck in the shut off position meaning that no fuel can be injected,you will need to remove the cover that the bleed valve is on,first turn off the fuel,then clean the cover and all around it,remove the bolts,tap the cover to loosen it as you don't want to break the gasket,with the cover off have a second person move the lever so you can weigh up what happens,the rack gets pushed to one side for the stop and the other to run,gently push the rack across to the run side,put it in stop again and then run several times till it moves with the control lever,leave it in the run position,clean out the housing and put the cover on,turn fuel on and bleed,word of caution don't loosen or tighten anything under the cover as you don't want to upset the settings.
AJ

dpendzic · Aug 23, 2017

Thanks AJ---thats what i was worried about--under the 3 plug bolts there are 3 different valves in there and was worried that valves and springs would pop out if i remove the cover?
also other guys tell me that a sleeve metering pump doesn't have a rack--some sort of linkage to raise and lower the metering sleeve?

AJ. · Aug 23, 2017

You are correct in saying it is not a rack I think the proper name is sleeve control shaft,when lever is down it in stop when up its run,its a good idea to leave the throttle on full after the engine is shut down.
AJ

Penn · Aug 27, 2017

Aj I have borrowed my neighbours 951B a few times and on one occasion it did run out of fuel and while bleeding it I did notice it had an in line injector pump like the one in the picture point being I thought all inline pumps had a rack,is this just terminology or slang or something new.
P

AJ. · Aug 28, 2017

Well it was new back in the seventies,the term rack is commonly used when referring to the fuel metering,in the old in line pumps like Bosch the fuel was metered by the rack turning the pumping elements within a bore,the elements had a spiral groove and the rack controlled the amount they turned which in turn controlled the amount of fuel injected,the sleeve metering pump like the 951 differs that it is the sleeve that is moved up and down therefore there is no rack but instead a control shaft with four yokes attached to it that lift and lower the sleeves when the shaft is turned by a crank on one end,turning the shaft to the engine side shuts the fuel off and turning it to the outside turns it to run.the best way to avoid it sticking is to put the throttle on full after shutting the engine down.
AJ

941B Won't start

dpendzic

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AJ.

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dpendzic

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AJ.

Well-known Member

Penn

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AJ.

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