How to change impeller on yanmar 1gm10 deisel marie engine

Yanmar TNV Cylinder Head Bolt Torque 

TNV82A
Step 1 = 30.0 Nm
Step 2 = 61.7 Nm

TNV84/88
Step 1 = 41.1 Nm
Step 2 = 85.3 Nm

4TNV94L/98
Step 1 = 49.0 Nm
Step 2 = 103.1 Nm

4TNV106(T)
Step 1 = 88.3 Nm
Step 2 = 188.0 Nm

I have no idea what a Yanmar is.

cylinder head torque for a yanmar 4tne94 engine in your google browser and a service manual choice will come up.

only in a diesel equipt truck

do you have fuel! is it petrol or deisel! have fuel filters ever been changed?
if its a deisel you may have an airlock, if its a petrol then its the EMS (Engine Management System) and that could be costly.

I would suggest just using a redundant wire to use for your tach.

I hope this helps.
Roy

take of the fuel sender hose of tank and be prepared to catch any spills wen finshed fill with deisel

do not understand you what you mean. assuming your car was ok before you changed f/filter you need to bleed the fuel system of air. esiest to do would be to loosen fuel line at the injectors and have assistant crank the engine while you observe for clear fuel leak without any air bubbles from fuel line.tighten fuel lines and start engine. might have to repeat a few times. good luck.