Rebuilt pump will not run

[ORCoaster]

Are you sure about getting that little tab into the delivery collar just right?  Or is that allowing the fuel to go back into the pump instead of out the back end as it should?  You did say you get nice big pulses of fuel from the back of the pump. 
Did you air any of the pieces where something might be stuck in a port someplace?  Those holes in the head going to the delivery valves?  Are those plugged?

Other than those ideas I am tapped out tonight.  To many different things going on in the brain about work today.

I have been multi-flogged. 

[burn_your_money]

Do you have a steady stream of fuel out the return? Do you have the in and out banjo bolts in the correct place? Any chance you put the control collar on the rotor on backwards?

[ross1905]

Yes good flow from the return, in/out banjos are the correct type in the correct places. Can pop the top off again to double check the collar but that should be correct, especially as this is the second time it's been rebuilt. Personally find it odd how it'll pump fuel out of the pumping chamber no problem with the centre plug out but gets upset when trying to flow through the delivery ports. There can't surely be anything wrong with ports the head, it isn't even mechanical...everything was and is very clean.

[ORCoaster]

ross1905,  The way I read the information so far you have the front side of the pump working and it is delivering to the secondary.  The problem is that stream you see coming out the back plug is not getting compressed as the cam hump comes up.  My initial thought is still on that control collar spilling the fuel to the inside of the pump.  That action is tied to the parts under the top of the pump right?  Those two springs that you have to goop up with Valoline to get them to stick in the head have to stay in place when you bring the head down on the pump shaft.  I goo up the other springs too the big ones to keep them from moving as well.  Vasoline is just petroleum jelly and the engine will love to eat it like dark chocolate so don't hesitate plastering it in those holes. 

Could you just have the fuel screw out too far?  I have done that in the past.  You need to back it out to get that top cap on don't you?  Maybe it is just short on fuel and not compressing enough to fire it up. 

Seriously thinking on this one for you because it is so easy to forget something or overlook the right position of a piece on that IP.

Keep in touch.

[ross1905]

Thank guys, we've got somewhere!! (took some provoking!)

I put the pump on a crate engine I had as it's easier than pulling the car apart each time.
Rebuilt again, haven't changed anything I've ever done apart from getting rid of the KSB, changing the timing piston and capping off the front as I didn't need a KSB on this car.

So after a lot of cranking and a lot of starting fluid I finally got it to fire up. It runs fine, smooth, everything working as it should.
However, it doesn't have a stable idle (unless it's at around 1500rpm). It also is very lazy to rev - as in if you pull it flat out (max travel screw removed) it will redline but it takes a while to build its way up there (almost like holding the throttle half way down and waiting). Terrible throttle response.
No amount of playing with the max fuel screw cures this, just more smoke and then a 3000rpm idle haha! - its almost like the control collar isn't being moved far enough.
Played with the throttle arm positioning on the throttle spline, no difference.
All I can think of is it's all to do with the governor system surely? I've always been skeptical as to what EXACTLY the effects are of the position of the "governor adjustment shaft". Normally I just count the threads and put it back where it was and its fine but this is the only thing I think could cause this - hear me out:

AFAIK - The static position of the sliding sleeve on the governor determines how far back the starting lever sits when the pump is stationary. This determines the positioning of the control collar for starting. If the sleeve is screwed in too far then the starting spring cannot allow the starting lever to 'lean' back far enough to move the control collar far enough for sufficient starting fuel - yes? (hence the terrible starting maybe?)
Then adding to this, once it has finally started and the flyweights are spinning, it has started to move the sliding sleeve slightly to push the starting lever back to the idle position (which is now too low hence the need for more on the max fuel screw to get it to idle). Then, as the throttle arm moves the tensioning lever for more fuel and the pump speed rises, this causes the flyweights to come out farther and push the sliding sleeve against the leverset to start to cut fuel delivery. As the governor shaft is set in too far, it is cutting fuel too early and you're constantly fighting against the governor hence why the pick up is so lazy as I believe it is stretching the main spring almost all the time. So all I can think of is to back the governor shaft out somewhat...what do you think to my theory? Sorry for another huge post

[sgnimj96]

seems like more fuel screw would be in order, 
I had to adjust fuel screw and the idle/throttle shaft till I found the right balance after pump reseal
here is some info on the nissan LD20 pump that is similar to the VW application (don't confuse w/ the LD28 info)
: https://docs.google.com/gview?url=http://www.waghornswood.net.nz/Manuals/Vehicles/Nissan/LD20_LD28_Manual_pdf/ld20_ld28_manual_ef.pdf may answer some questions and show how the governor operates

[theman53]

So after a lot of cranking and a lot of starting fluid

             This is what is known in the internet world as a fail. For all those reading at home, you do not use "a lot of starting fluid" in these older IDI diesels that have a steel pre combustion chamber press fit in an aluminum head. Especially ones that are this old. Cracks in the pre chambers, broken pre chambers, cracked rings, and more fun stuff can result.

          If you have to things that are a lot less explosive like wd40 should start the engine in a little safer manner. Still, do not spray so much, just mist, you can hydro lock and bend stuff that way too.

          You can now return to your regular scheduled reading.

[libbydiesel]

I've done work on these IDI diesels for more than 20 years now and have never once used starting fluid.  I've always just fixed the starting issue rather than using an infected band-aid.  These are simple engines and start without issue provided just a handful of things are correct.

[ORCoaster]

I agree Libby,  But to be a master of that handful is the key.  I don't think it takes 20 years to do that but my guess is that those without a lot of diesel experience find it more difficult than it really is.  The basics start with throwing out much of what you know about gassers.  Once you switch to the correct mindset about tolerances, torque and timing procedures all you really need is a good Bentley and things fall into place.  At least that is how it works for me.

I was finishing up my repair of my engine and was tightening up the head and a buddy drove up, I was doing it in the street, and he was just marveling at how it was no big deal for me to pull it all apart and put it together AND have it run again.  I look through Craigslist here and generally there are at least three or four descriptions that mention pulling off the timing belt or rebuilding the engine and now it won't run.  OR trys to start but it won't.  If I had more time and money I would buy them all and flip them for a few hundred just to have them running.

[libbydiesel]

Starting fluid does not help diagnose a diesel (anything it might reveal could have been found out more effectively in other ways), it certainly does not assist in any repair, and it can cause significant damage to IDI engines.  There is not any reason to use it and significant reason not to.

[ross1905]

Thanks for the replies, I too have worked with these years and know the do's and don'ts with starting fluid.
Everything said is correct and I don't use it on these, however, the pump's being tested on a crate engine which is useless for anything other than this purpose - so I care not about the damage that can occur (the engine was initially scrap). It got it running, though without flattening batteries. This at least gives me an idea of what's going on with this pump.
Anyway, with that cleared up I'm going to move the control lever a spline each way (again) to see if this gets anywhere and possibly take a look at the governor shaft. I think we can all say that it's likely to be down to the positioning of the control collar (it's just finding which part is influencing it to be in the wrong position at the wrong times!) I'll report back asap