20 seconds before glow plug light extinguishes seems much too long. Should be 14 seconds maximum when there is a fault. Maybe there are slight variations between engines.
sensor on the Dti engine I offer my thoughts or assumptions about its function:
1) A fault with
/ engine speed sensor will cause the warning light to illuminate.
2) Engine will still start but goes into a safe mode.
3) Dti engine does not rely on
sensor to start.
4) Injection pump advance is at zero position when starting.
sensor info and start of injection info from sensor in no 1 injector to adjust injection advance and volume of injected fuel.
Nostromo1956 has already checked and confirmed that injectors are getting fuel, see post 4.
There is another way of checking if my 2 fault conclusions are correct:
Try starting without preheating, i.e. don't wait for glowplug light to extinguish. Do this check on a cold engine. Please report finding. Engine should be very difficult to start if injection timing is retarded and engine is cold and glowplugs not red hot.