Try spraying a 2 second burst of starting fluid into the throttle body air inlet while the throttle is held partly open. Then quickly slip the air hose back on the throttle body and try to start the engine. If it fires briefly and then stalls; fuel is not reaching the engine. This can be caused by a clogged fuel filter, a bad fuel pump relay, or by a bad fuel pump.
If starting fluid does not make any difference, the spark plugs may be fouled, or the timing belt may have jumped out of synch. Remove the spark plugs and inspect them. If the porcelain insulator in the center of the plugs are wet or black with carbon; the plugs are fouled. Install a new set of plugs; perferably the recommended Autolite number for this particular model. It would also be wise to replace the plug wires and the distributor cap if the plugs were fouled.
If the plugs are clean; test the compression on all the cylinders. If the compression is less than 125psi in all cylinders; the timing belt has jumped, and must be replaced.