More info is needed.
When you say it "Cycles", where does that fall into the following sequence....
1. Call for heat
2. Inducer starts(exhaust)
3. Pressure switch closes( connected to inducer via hose)
4. Ignitor glows or sparks
5. Gas valve opens and burners light
Does the ignitor glow or spark at all?
Do you see the exhaust working?
Sometimes the small hose that runs from the exhaust housing to the pressure switch will get clogged. Blow it out and don't forget the inlet and outlet.