long cranktime on 1.6td

[vwking]

I have a 1981 rabbit pu with a 1.6 idi td from a 1986 Jetta.  My father was a vw dealer mechanic from 1968-1993 and still repairs them as a hobby business.   We rebuilt this engine 800 miles ago,  - 1 new piston, new rings, bearings, rebuilt head, rebuilt turbo.  The injection pump was rebuilt within the last 2k miles.  The engine has a long cranktime when starting (up to 30 seconds cold, 5-15 seconds warm).  The engine was rebuilt because the lower radiator hose blew off and overheated.  The engine runs quite well once started, may lack in power slightly but is smooth.  Blows white smoke from exhaust once started but not a tremendous amount-just enough to notice it.  Timing has been double checked-all right on.  No signs of fuel leakage from under truck or engine compartment.  Injection pump was timed at 1.0mm.  Starts better but still abnormally hard 5-10 seconds if plugged in so I believe all glow plugs to be O.K. Any suggestions?  I do not have clear fuel lines on the truck, could sucking air somewhere cause this?  could the injectors be leaking fuel down?  Could it be leaking fuel back to the tank?  I have tons of non turbo idi injectors- could I substitute them for the turbo injectors to see if it helps (no pop tester)?  Dad is very familiar with non turbo 1.6 engine, just never saw many with a turbo.  Thanks for your help

[libbydiesel]

I do not have clear fuel lines on the truck, could sucking air somewhere cause this?

Yes.

could the injectors be leaking fuel down?

It's probably not impossible but I've never seen it and I don't think it would cause your issue.

Could it be leaking fuel back to the tank?

Yes.  Any leak at the pump or injector jumpers can cause the fuel to drain back to the tank.  Adding the clear lines to and from the pump would tell you a lot.

I have tons of non turbo idi injectors- could I substitute them for the turbo injectors to see if it helps (no pop tester)?

Yes.  If you do, you should time it to the non-turbo timing spec.

[ORCoaster]

Listen to Libby on his suggestion for clear lines.  That will show the single biggest fuel issue that these pumps seem to be prone to.  I didn't see where you tested the GPs.  You believe them to be good but I would test them to be good.  And they may be good but some other part of the electrical system is not and that is causing the hard start, smoke and other issues. 

If you rebuilt this engine have you done a compression check on it after these 800 miles.  Some breakin is going to be needed to get it all to lap together and get you that great 400 plus PSI but right now it might be showing low enough that it may be cause of the trouble. 

Just some thoughts. 

[spltshft]

I agree with ORCoaster,  my first check would be the compression  of each cylinder. A little smoke on a cold start for a diesel is nothing to worry about as long as it isn't bellowing.