Chevrolet: Engine Thermostat Gauge, fuel pressure regulator, engine thermostat

Question
Hello Mr. Singh... I just recently bought a 1995 Camaro RS with about 158 thousand miles on it... The car is in excellent condition overall, and i couldnt have asked for better... 2 little problems i noticed... The fuel gauge fluctuates alot... It will never give me a very accurate reading... That doesnt really bother me as much as the next thing...

The engine thermomstat gauge does the same thing... For example, at freeway speeds, the car runs relatively cool... Once i stop though in normal traffic, it goes up and up... Then Itll drop all of a sudden... The same cycle repeats... Itll sometimes reach the red zone, then drop again to about 3/4 of a way... Should i be worried?  

Answer
I'm guessing you have an aftermarket fuel psi guage hooked up. It will always go up and down as you drive. The only way to get an accurate reading is to disconnect the vacuum line at the fuel pressure regulator (do this with the car not driving). If the fuel psi is good with the line disconnected, then all is fine.

As for the temp guage, sounds like you have an air pocket somewhere in the cooling system or one of your rad fans isn't coming on.