Reasons an injection pump can loose its prime overnight?

[billybobf]

might just hide the problem untill after startup? if the input for the IP is leaking into your timing cover it wouldnt appear to be leaking from the IP but will kill your timing belt quick too

[bbob203]

might just hide the problem untill after startup? if the input for the IP is leaking into your timing cover it wouldnt appear to be leaking from the IP but will kill your timing belt quick too

thats all true i only offered that as 'quick' solution to keep from having to crank a dry pump until a more permanent fix was implemented.

[Thezorn]

The pump has had clear lines from the hard lines to filter since a few days after I got it. It always had the seldome air bubble going into the filter from the tank and had the same amount filter to pump. When I get back home this week Im replacing all the line from the tank to filter in hopes there is magically something in there that has opened up a pin hole.

[smutts]

X2 on getting shot of the warm up valve, using the earlier filter, no more bubbles, no more smoke, and more grunt. Happy. Until the fuel freezes.

[Thezorn]

Right, just to be clear, you have half of the clear lines that you need for diagnosis of the issue and they are showing that the issue isn't on the supply side.  Regardless, you're going to swap out the lines on the supply side this weekend.  If it were me, I'd focus my attentions differently.

I was unclear in my past post that it has clear fuel line from the tank all the way to the pump, supply and return.

Look 2 posts up and youll see how I said that the only place I have ever seen air in the system is in the supply line pre filter.
I replaced the part of the hardline that goes through the frame rail to the fuel filter believing that it was my problem, and it was not.

Unless im missing something, it would make sence for me to replace the line that has been the only sign of air getting into the system since day one..?

Im hopping my local vw shop will have the mk2 diesel filter that Ive been waiting on tomorrow or sometime in the coming week.

[Thezorn]

When you first start it up and look at the return does a bunch of air/foam come pouring out of the pump on the return side?

Yes, It takes a couple seconds, but that is exactly what happens

[Thezorn]

Went and looked at a few things in the car today. First I figured I would check a few things in the pump.
I looked far and wide for any sort of fuel leak and came up dry. I then undid the banjo bolt for the fuel feed to the pump to check if the pump still had fuel in it, the pump turned out to be full and the feed line also was.
I figured Id try and start the car and see what happens, It started second crank, I let it idle for a few minutes then shut it off.
I then went back into the engine bay and noticed that I had the return line's fuel shut-off in the closed position. As soon as I turned the fuel shut-off open there was a rapid vacuum that looked to pull fuel rapidly from the filter/pump. I turned the shut-off to the closed position after about 5 seconds of seeing this vacuum.
I then went back and tried to start the car again, this time it took about 5 or 6 times as long as it would for the car to normally start.

Now by the looks of it, unless Im not understanding the whole vacuum idea, which is more then likely, wouldn't this mean there would have to be a leak in the return line. The whole time the car was sitting the fuel supply line's shut-off was open.

This is confusing me more and more the more I think about it..which Isnt a good thing. 

[745 turbogreasel]

You installed a valve in the return line.
Ran with said valve closed for a bit and stopped the motor
Opened the valve , releasing all the return fuel  under pressure from the normally unpressurized side of the out banjo...
A bunch of that fuel whooshed by.

^ Did I read that right?
If so, I'm surprised you didn't blow off a return line.
Hard start afterward is a good puzzle though.

[Thezorn]

Yea I realized afterwards that the return was closed off, im still confuesed on the hard start right after it was running though.

[Toby]

another quick solution might be a check valve between ip and fuel filter.

Where do you find such a check valve that will stand up to diesel. I have looked far  and wide for one with little success. I find lots that are to stiff, but none in the operating range of the suction side of the IP. I have made some out of other things, but have never been happy with them.

[Thezorn]

I just used ones that were meant for gas... I dont plan on having then in for very long, just until I get all this resolved.

[Toby]

What car did it come off of? I have never been able to find a low pressure gas check valve. I know they exist, since I have held them in my hand, but never have been able to find what they are off of or where to buy one.

[Thezorn]

I just used regular fuel shut offs, no check valves. Not sure where you could get a fuel rated check valve personally.

I finally replaced got around to replacing all the fuel lines last week. After spending half the afternoon making sure there was no leaks and priming the lines/filter I still had the same problem. I was stumpted.
Finally after replacing all the lines, it clicked in my head, that everytime I would start the car it would have a huge cloud of white smoke as soon as it would fire up, meaning it was getting fuel the whole time and not combusting. Meaning that either it had such bad compression that it cant start, or it has no glow plugs.

When I built the engine last winter I did the "pimp your glow plugs". The reason I never suspected anything was wrong with the glow plugs is because my soleniod would still click whenever I turned my key on, but when I tested the GP's for power there was nothing. I made sure that there was no loose connections and that everything was in working order, finally replaced the soleniod.
First crank it started up..
I still dont know why the soleniod would click but not transfer power, possibley a corroded or broken internal post?
But its working now and I am very happy about it  

[92EcoDiesel Jetta]

Do you have a MityVac? Seems like you replaced a lot of parts unnecessarily.

[ORCoaster]

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.