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1.6TD won't idle - I'm stumped

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Canola J:
I just completed an engine swap to the 1.6 TD and have set the injection pump timing to 1.00mm, which seems to be about the minimum to keep it from smoking (white).  The problem is that it won't idle worth a darn.  I've adjusted the screw that sets the return position of the throttle, but I have to set it such that the engine doesn't drop below ~1200rpm.  Even then, sometimes it will drop out, sputter at a few hundred rpm for a few seconds, and then die.  I've checked the pump mounting , since I heard that a vibrating pump can sometimes be a culprit, but all four bolts are tight and the brackets are not cracked.  The air line from the intake manifold to the advancement device is not leaking.  It's better with the cold start lever out.   I haven't tried playing with the fuel enrichment screw yet.

I don't think it's compression, because the engine will run just fine at lower rpm.  It just won't stay running if I don't nurse it a little.

My suspicion is that there's air somewhere in the fuel pump or injector lines, and here's why:  Upon starting, I consistently have to crank the engine over about 30 revs before it starts, at which point it lights up just fine.  It's as though there's a bubble in the injector line, so it takes a while to compress the bubble and get up to pressure.  If the engine's been running and I turn it off (or it dies), it will start right back up again.  But the longer I wait, the more the "bubble" re-expands, and the longer I have to crank it.  This might explain the idle problem, if at ~1000 rpm the pump can't keep up with the bubble expansion, and injection pressure is lost.  The only problem is that I've repeatedly bled the entire system, with no change.  I have another NA 1.6 (SVO converted), which I've run dry numerous times, that I've never bled and yet have never had any problems with air in the lines.

Is there some place where a bubble could get trapped, is it a fault with the pump, could it be a leaking injector, or do I just need to play with the fuel enrichment?  I don't have enough experience to be able to diagnose this one...

Thanks for any assistance!

toomanycars:
Checl out the posts on "bubbles in the fuel line". Might give you some clues.
Peter.

Hammy:
Did the engine sit for a while? I had one that had sat for a year, and air got inside the pump during that timeframe, which made a mess of my pump, and injectors. I couldn't get it to run properly, so I swapped them out for another pump and injectors. Ran well after that.

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