How To test the Diesel High-Pressure system

[FrenchMike]

Hi all,

In case of non starting (preferably hot),Camsensor is generally incriminated.
But we have to know the behaviour of the common rail pressure in order to rule out a possible injector leak back.

Here is a easy way to do it:

YOU NEED:

-a lowcost multimeter (DC 2 volt range)
-one or two alligator clips with pin associated (as already describe somewhere)


PROCEDURE

1 Disconnect the camsensor.
2 Pin throught the insulation of the blue/black wire (the other green/brown
is the ground.
to pick up the fuel rail pressure signal.
3 turn the key position 2 (you must read 0.5 volts)

4 Crank for 4 secondes then release the key.

If you get a chart like the green one,then,you have no significant leak.





Camsensor test:



Low pressure test



High pressure test.




In case of low values,an injector leakback test is recommanded.




Check the HP pump regulator gaskets as well.




MAF test




Cranckshaft sensor is easely tested by looking at the tachometer needle during cranking.

Don't forget;if starting with easy start,it's not an electrical issue but likely an injector fault.

Mike

Enlarged Thumbnails.....