Got a 92-SC400. Recently I've noticed a power decrease below 2500 RPMs. When I WOT it from a dead stop I get minimal traction loss (1/4 wheel spin at most) then sluggish acceleration below 2500 RPMs, after that it goes good as usual. The car has been maintained well, recently new sprakplugs, wires etc. Anyone have any suggestions or similar issues. Thanks.