D318, low fuel pressure

New bypass poppet with a soft seal might make a difference. I would get a spring while I was ordering it. The surface the poppet seals against can get a groove worn in it. That can be machined or carefully filed back flat if necessary.

new filters and all new fuel. I will go with the spring and seal. Seal mating surface is ok. Thanks I see the only item listed is the poppet. The seal must be bonded to it.

What have you got for actual (measured) clearances between gear tooth tips and housing plus end case clearance?

What have you got for actual (measured) clearances between gear tooth tips and housing plus end case clearance?

Is there a specification for clearance?? Pulled the relief completely out. Made a heavy duty gasket that covered the relief valve hole. Fired motor up, fuel pressure still "0" when cranking, a little better when running but still not in green. Pulled complete pump, there is wear. Wondering if new gears are available. Thinking of about lapping down the center housing end plates and gears.

Going back to my first post. It takes 30 psi to get the gauge into the green. Studying the engine book, and it says the pump supplies 15psi. Problem is bad gauge. still going to lap some wear off the end plate and center housing.

New pump clearance is 0.001 to 0.0022 (total) between gears and cover and gear teeth to housing.
Maximum allowable wear (total) is 0.0035.

[quote="Old Magnet"]New pump clearance is 0.001 to 0.0022 (total) between gears and cover and gear teeth to housing.
Maximum allowable wear (total) is 0.0035.[/quote]


My gauge never reads anything until the Deisel is running. Once it starts gauge goes green. I've checked regulator and lapped end clearance down to no avail. Engine starts with no juice after my ring job. I figure as long as the tower is full there should be enough fuel for the injection pump to operate. I attribute the lack of primary pressure due to much lower cranking speed than Deisel idle speed after it starts.