As long as you can sink the gauge at least 2.0 mm into the pump at TDC,then it's long enough.
Are you sure your getting full travel of the pump ? A lot of time they get sticky and will be hard to rotate.
Loosen the injector lines to make it easier.
Are you sure the timing belt is good ? If it's stretched,the pump timing will be retarded,and you will have to rotote the pump a fair ways to get it set right.
Start over and retime the belt first.Make sure you rotate the pump back (towards the front) so you will have some adjustment room afterwards.
When you install the belt,line crank up at TDC.Rotate IP pulley clockwise so it goes slightly past the hold for the pin to engage,and old it by hand.Hook the belt over it so teeth engage on belt,then release the IP pulley and rotate counterclockwise to remove slack.IP lock pin should now be lined up (or use a socket instead).If the locking pin or socket slides in,and is level,or pointed slightly down,you good to go.If it's pointing slightly up,then your belt is stretched,or the IP bracket is crooked.
Once you get it lined up,then slide the cam pulley under the top of the belt (with cam lined up),and tighten the bolt.Tension the belt,and then rotate the engine a few turns by hand,and then recheck to make sure.
Once you get the belt right,you should be easily able to get more than .085 mm at the pump.
Line up motor at TDC.Install dial indicator and tool and sink it to about 3.00 mm or .150".Rotate engine back until dial indicator stops moving,and zero it.Rotate slowly back to TDC and read.Now you can rotate the pump to make you adjustment.Don't forget,when setting timing,to take belt slack into consideration.I always push down on the belt between the IP pulley and the cam pulley to remove slack.This will give you a more accurate reading,and you will see the timing actually retard some when you do so.Set it so you get the timing you want when the belt is pulled tight.I usually set it .005" advanced,so you'll be right on when the blet is tight.
EDIT - Forot to add,you can push the dial indictaor arm in with your finger (where it comes out the top of the dial) as you rotate the motor back from top dead center to make sure it goes all the way in.Sometimes it will stick,throwing off your "zero" reading.