Cockshutt 1650- lift pump

CJN1

New User
Hello all,
Fuel has been entering into my oil on my Cockshutt 1650D. It has been mentioned to start with the fuel lift pump as they are known to fail. I have the pump off and disassembled. I can't see any tears in the upper or lower diaphragm. When they let fuel past where do they fail? Lower diaphragm seems to be the critical last stop before getting to the block but can't see any obvious damage.
 
(quoted from post at 14:34:33 05/26/18) Might be the injection pump also, if the brass tube is grooved badly over time the drive shaft seals will leak too.

After finding no obvious problems with the lift pump I put it back together and plugged the output line and blew in the input line and could not detect a leak. Installed on tractor with lines tightened up but not tight to the block and cycled the lift arm and I couldn't see and fuel leak out the back.
This fuel in oil problem started after one of my pencil injectors let go and it started knocking. Replaced the injector and knock fully went away. Fuel coming in at about half a quart a hour running. None when not running. The frequent oil changes are getting expensive! I guess the injector pump needs to come off. Will need to read up on it first. Thanks!
 
Does the engine have white smoke and miss while running? Can also be a weak/dead cylinder with low compression causing trouble too. Neighbor had a 1950T like that, he couldn't hear it miss, but was getting fuel in the oil still after the pump was repaired, no change. Any time there's white smoke, fuel is not burning. It will go past the rings into oil that way too. Confirm by taking the fuel away from the suspect cylinder by loosening the fuel line, if the smoke clears, that's the bad cylinder compression wise..
 
(quoted from post at 19:19:29 05/26/18) Does the engine have white smoke and miss while running? Can also be a weak/dead cylinder with low compression causing trouble too. Neighbor had a 1950T like that, he couldn't hear it miss, but was getting fuel in the oil still after the pump was repaired, no change. Any time there's white smoke, fuel is not burning. It will go past the rings into oil that way too. Confirm by taking the fuel away from the suspect cylinder by loosening the fuel line, if the smoke clears, that's the bad cylinder compression wise..

It runs rough when cold start up but runs smooth and almost smoke free when warmed up. There is a very slight white smoke still. But there always has been since Ive owned it. Touching the manifold from cold shows a couple cylinders are slower to warm up. But all drop rpm when injector lines are cracked. I will watch the smoke when cracking the lines next time. Does half to three quarters of a quart not seem like a lot of fuel getting in?
If it is the injector shaft seals what do I need to do before removing the pump?
 
Before removing the pump, take off the two screw timing cover on the pump side. After fuel stops flowing out turn the engine by hand to align the timing marks and check the timing at the flywheel. Remove/replace the pump with the marks aligned. I still get pumps in for repair that were not timed at removal sometimes, makes for more work going back together..
 

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