Hey: New guy here, I own 2 vettes one of which is a 87 roadster. I'm experiencing an intermittant surging of engine with tach jumping approx 1000 rpm up and down above 45mph or so. Corvette mechanic suggested a clogged injector and suggested I try several tanks of Chevron before tearing into the injectors. This problem is so intermittant that I have a hard time accepting this. I've changed the fuel filter, no difference! Any suggestions?