Reasons an injection pump can loose its prime overnight?

[92EcoDiesel Jetta]

Seems like you replaced a lot of parts unnecessarily.
The story of a mechanics life I say.  Live and learn to do better?

Check valve?  How about this one.  
http://www.wvodesigns.com/products/wvo-conversion/hose-fittings/sst-check-valve-for-99-02-ford-7-3-psd.html

A wee bit spendy.

That check valve would work but you have to put some adapters in to fit the VW IDI hoses. Why not buy the VW check valves with the correct size barbs? There's one on the fuel sender and one on the water separator under the car on some model years. These check valves are also on most TDI's

[Thezorn]

Seems like you replaced a lot of parts unnecessarily.
The story of a mechanics life I say.  Live and learn to do better?

Check valve?  How about this one. 
http://www.wvodesigns.com/products/wvo-conversion/hose-fittings/sst-check-valve-for-99-02-ford-7-3-psd.html

A wee bit spendy.

That check valve would work but you have to put some adapters in to fit the VW IDI hoses. Why not buy the VW check valves with the correct size barbs? There's one on the fuel sender and one on the water separator under the car on some model years. These check valves are also on most TDI's

No kidding

[Toby]

That check valve would work but you have to put some adapters in to fit the VW IDI hoses. Why not buy the VW check valves with the correct size barbs? There's one on the fuel sender and one on the water separator under the car on some model years. These check valves are also on most TDI's

What cars have a water separator under the car? Or did you mean under the car near the water separator? Also which ones have the check valve in the tank? Having a couple of these in the tool box would be a great troubleshooting aid.

[745 turbogreasel]

Summit racing has a couple kinds  ~$20

[belchfire]

Mc Master-Carr(.com) is an industrial supplier that will sell to the average Joe and has about any kind of chech valve imaginable. I got a brass one w/ stainless ball mfg'd in 1952 off of E-bay for cheap.

[ORCoaster]

http://www.mcmaster.com/#standard-check-valves/=h7jmrw

More than enough to choose from.  Some already have hose barbs on them.  15 bucks

[92EcoDiesel Jetta]

That check valve would work but you have to put some adapters in to fit the VW IDI hoses. Why not buy the VW check valves with the correct size barbs? There's one on the fuel sender and one on the water separator under the car on some model years. These check valves are also on most TDI's

What cars have a water separator under the car? Or did you mean under the car near the water separator? Also which ones have the check valve in the tank? Having a couple of these in the tool box would be a great troubleshooting aid.

My Ecodiesel had a water separator under the car (since removed). There was also an inline  check valve coming off a barb of the separator going to the IP , and an inline check valve going to the sender for fuel return (not inside tank.).

[srgtlord]

I know my pump loses prime overnight, but with a simple  low pressure electric pump, problem solved