I am a development test engineer for pump drivers and as I look at all the answers I say possible or not correct, some of the suggestions might endanger unexperienced gas pump clerks… from experience I suggest not to make assumptions about the reason of why the pump is running slow, the reason can be one of hundreds of possible reasons… as simple as sensor got gas on it, to pump over heatig to more than 1000 other reasons… one of the most dangerous things that can be done is repeated reset, to clear the fault, some VFD variable frequency drives reduce the speed when overheat reaches a limit so the pump will be run slower to keep the temperature of the motor under the set limit. Resetting the power might clear the memory and cause the motor to over heat and start a fire… my suggestion is to treat this issue as a sefty response and a dangerous one and contact your gas pump technician ASAP, this can be costly if not fixed or if bypassed… Joseph Morse