Plugs or timing

Sounds like an ignition timing issue. consult a manual to find out what the correct timing is and then check your timing to make sure it is correct.

possibly depend what you mean by first time a few turns after glow plugs light turns off should start it straight away people have this habit of turning the car over before the glow plug light goes off do it a few time s to make sure the plugs are warm if its realy strugaling to start its probably the glow plugs there a bit expensive but not pocket braking

Check timing belt, possible jumped time, stripped teeth, etc...

i would start easy, and go with a plug change, a code telling you about missfire is a good indication that a plug or plug wire has gone bad. pull that plug and check for oil on the plug, and carbon, more then likely your plug is bad. but dont just change that one plug you should do them all. i think if i remember the plugs are a pain to get to, but you can do it, if your not used to working on cars just pull one plug at a time, so you don't screw up the firing order, get an extention for your ratchet as well a swivel end, for those weird bends and angels. "one plug at a time i would also change those wires,"one wire at a time" also make sure you have pulled the black ground wire off your battery, not only is this safe but it will also reset your cars computer and the check engine light will be off, do another code check after you have finished replacing the plugs and wires. if no engine lights are on, turn your key three times to the start possition without actually starting the car do this three times and then watch as codes are shown to you. "this does not apply to all cars", if this dont apply to your car go to auto zone and get the free key to plug into the box right under your dashboard, "you could also make one with a paper clip". then see codes, if no codes are shown your good to go, im sure it's a bad plug and wire problem. how does she run now? i mean is she giving you a hard time starting? or is she running rough? start the car pop the hood and listen to the engine while idle, should be smooth unless a plug has gone bad, if one has you will here a drop in idle, or smooth engine idle. you will actually see the engine **** a bit when the idle has dropped, or changed, i swear this sounds like you need a plug change, i had one of these cars i loved it,

If the car didn't start after the timing belt replacement, it is highly possible the timing was not reset correctly, causing a valve to be bent by the piston, and pushed into the spark plug.

check to see if fuel spits out of the hole.

timeing belt

it sounds like a glow plug issue. perhaps a bad glow plug relay. I would think its the relay if the problem comes and goes. If it were a bad glow plug the problem would be constant. check for volts at the glow plugs next time the car acts up. If you find no volts, tap on the glow plug relay next time you turn the key on. This may cause it to activate. if so then replace relay

Just till the plug / light glows then start, if you hold it too long the glow plugs wil burn out causing hard starting.

Have you checked the heater plug relay?