I have a 1991 Camaro Z28 with an overheating problem. When the car gets to 230 and the fans kick on it immediately dies. I have an aftermarket fan switch that should turn the fans on at 185. I think the gauge might be inaccurate but I have not checked it yet. If I rev the engine when the fans are about to come on I can keep it running and let the fans cycle on and off several times, but as soon as I let off it dies. At idle before the car gets hot it runs fine and doesn't die. The car has a new radiator, water pump, fan switch, and 160 thermostat. It circulates water fine, but could the 160 thermostat be the problem. Would a 180 be better?