Rough Idle with high Idle rpm

[Super T]

Engine is 1.6L TD in a 92 Jetta, the idle is too high and unless I have the cold start handle full out it idles rough, leads me to believe my pump timing is off but I am very new to the diesel engine. Drives fine, sometimes have hard starts. Injectors? Injection Pump? Usually idles at 1100 to 1200 even around 1000+ with handle pushed all the way in. On a side note which one is this fuel screw people keep talking about?

[Smokey Eddy]

This isnt one of our pumps but its identical. just more out puts and bigger.

There she is.
It has a 13mm nut on it (i think its 13) you have to losen off before you can turn it. turn it VERY slowly, it's sensitive.
1/3rd at a time i'd say is safe.

About the rough idle, it could be a sticking injector in which case it would have to be taken apart and cleaned with brake cleaner/oven cleaner

Put a screw driver just on the injector and put your hear right onto the butt of the driver and listen to all 4 like that. You make hear a definate knock sound. that's your sticking one.

search injector removal stuff on the search here and you'll find everything you need to know about removing them safely and putting them back in all the while not damaging them (they're very sensitive).

[burn_your_money]

How many air bubbles do you have being drawn into your pump?

[Super T]

I have noticed a few bubbles in the lines, small ones not often either. Where is a common place for air to get in?

[Smokey Eddy]

the water seperator under the passenger rear seat. (I removed mine entirely and threw it out)
the lines that connect to the fuel filter (cut them and put them back on if they're cracked and frayed)

[Super T]

The lines to the fuel filter look fairly newish and I don't see any fuel leaks at them. Doesn't make sense to me that I could have no leaking fuel but air in the lines. But I've been wrong before. I'll have to check my water seperator.