Pinging on 1997 Suzuki Sidekick

When Iam going up hills my engine starts to ping, I then shif into a lower gear and the pinging is less. The engine has about 97,000 miles on it, the engine does not smoke or knock. The engine runs very well outside of the pinging. On a flat street it does not ping at all.

Asked by for the 1997 Suzuki Sidekick
Your Suzuki has a conventional distribution ignition system. Check the ignition timing, check the quality of gas (could water have got into the tank?). Check that the engines fuel air ratio is not too lean. EGR also lowers pinging by lowering cylinder temperature.