Need help with tracking down air leak in 1.9 AAZ pump

[Buji88]

Got it sucking fuel last by itself, and it looks good in that regard.

I kind of got it running last night, but only on one cylinder #3 was getting plenty of fuel. With glow plugs its actually fairly stable, shut them off it will slowly stall. but Im not sure why that is happening. The other cylinders seem to be getting a dribble compared to 3 which actually squirts. So I'm guessing there is a massive air bubble in the pump. Going to pull all the lines and start bleeding directly out of the delivery valves and work out from there.

I also have no throttle control, pulling on the lever does nothing for engine speed at all, but Im assuming that could be related to the issue that 3 is only getting adequate fuel/pressure.

Weirdly, it starts pretty easy, considering only one cylinder seems to be functioning.

[ORCoaster]

What a crazy bunch of weirdness.  Glad it is on your ride.

[fatmobile]

This one has me confused too.
 I know when it's not pulling fuel the accelerator doesn't increase RPMs.

 Did you try swapping a regular/input banjo bolt in place of the "OUT" banjo bolt?
Just to see if it's pumping fuel through the pump and maybe see if the OUT bolt restrictor hole is clogged.

[Buji88]

Well, Im getting it sorted one by one. I swapped the hydraulic head I had and bam, full fuel to all four cylinders no problem, and like instantly when bleeding the lines. So Im guessing a lot of issue I've been fighting has been my original head just slowly dieing? Not sure really but the 11MM I had just makes it run and start way more better. Now it has power again to move itself at idle. Still no throttle control and its surging at idle. But I think I figured that out to.

The device on the end of the timing piston (inlet side of pump) with the solenoid that goes to the internal governor (which is the hole I stripped) Im pretty sure this feeds the govenor/allows the fuel to escape from the back side of the piston while it advances. I'm pretty sure once I get this unblocked again will fix at the very least the surging/hunting. But I'm also thinking the throttle control as well since I believe the governor increases case pressure along with it. Its been a wild ride to say the least.

[Buji88]

This one has me confused too.
 I know when it's not pulling fuel the accelerator doesn't increase RPMs.

I bet this is all tied to my original issue. The pump is pulling fuel correctly by itself now, but because Ive blocked off the path from the end of that piston, it makes sense that Ive basically killed a major fuel path.

[ORCoaster]

Well done.  That timing piston has to have fuel on both sides of it to work as designed. The piston controls the advance of the timing of fuel delivery and if you don't have a way to make it push both ways then it just doesn't know what to do if you advance the RPMs.

Higher RPMs increase internal fuel pressure and that is what makes the piston move the little bit that it does.  So it isn't so much the governor but the overall RPM of the spin of the pump. 

Keep poking at it.  Fine tuning a Bosh FI pump is a long process especially if you don't understand the inner and outer workings of them.