I have an 86 GL wagon 4wd which detonates like crazy when accelerating at medium throttle. If you ease up on the gas a little it stops and if you plant it it stops. The car also gets +/- 23 mpg only, and I would think a slow car as such would do a little bit better. The car has a reman'ed carb (hitachi), new air cleaner, plugs, wires, distributor cap & rotor. A dude I know suggested cleaning out the EGR and testing the diaphragm, but he also though that detonation and pinging were different things, so I'm dubious it will work. Any help?