What will be the sign when the crank sencer is not working?
That year did not have a crank sensor on it.
The crank sensor is located behind the hamonic balancer
the sensor on the 3.3l mucury villager is integrated into the distributor
No you can not.
The marks are on the cam and crank sprockets, and on the timing belt. They all must match.
pcm or crank sencer
crank sencer, coil pack, or ecm
belt it self has timing dots on it, line it up with cam dots and crank dot.
There is no such thing as a 1987 Villager, I assume you mean a '97. The water pump is in the center of the engine in front, behind and above the crank pulley. To remove it requires that the crank pulley be removed, which may require special tools.
The crankshaft position sensor is at the rear of the engine where it joins with the transmission bellhousing. It is at the left (front) side, not far from the starter.
On a 2.5 4 cylider models the crankshaft sencer is attached to the bottom of the DIS assembly. After carefully lifting the assebly off the engine block, unbolt the sencer from the bottom of the base plat. replace the new one.