A method for starting a fast light-off catalytic reformer for producing hydrogen-rich reformate fuel from hydrocarbon fuel and air, the reformer having means for receiving flows of fuel and air, a reforming catalyst for reforming the fuel and air mixture, and an ignition device. A control system selects fuel and air flow rates to form a lean fuel/air mixture and operates the ignition device to ignite the lean mixture to produce hot exhaust gases that flow over and heat the reforming catalyst for a first length of time. Fuel flow is then stopped temporarily for a second length of time, and further ignition is terminated. Fuel flow is then restarted and adjusted to provide a rich fuel/air mixture which is directed to the heated catalyst for reforming into reformate fuel. Air flow may also be adjusted in setting the lean and/or rich fuel/air mixtures.