1990 Mitsubishi Eclipse....Engine Sputters Under Load...DSM woes

I have a 1990 mitsu eclipse 5speed with a 1.8... It has 150,000 miles on it. Under load after about 4,000 rpm the engine will sputter. The car will rev up to 6,000, but only if you roll the throttle on...The car will sputter after 3/4 throttle...There is no CEL....Any help would be appreciated....Thank you