i suspect you mean glow plugs!
that engine doesnt need them to start, they are for smoke emmisions when cold.
the only three common things that stop them starting are fuel pressure, injector wiring shorted out on the engine mounting, or crank signal.
do check no one has kicked the plug out of the control unit in the passenger footwell!
need more info, was it getting harder and harder to start, hot/cold?
does it go with easy start or a push?
tony, March 2011