my U-12 stanza will not raise rpm's above 5500 so far i have installed fuel filter,new tps,new MAF,air filter,Set idle to service manual,set TPS to service manual,replaced ALL
vac hoses,replaced O2 sensor checked fuel pressure (dead on) checked Fuel pressure regulator( Dead on) all my air intake equip is tight and no vac leaks where found,I am at loss on this situation and any suggestions would be an awesome help..