I have a 1990 RS 3.1 multiport. Replaced the intake gaskets because you could cap off the throttle body while engine was running and it would stay running (major vacuum leak). The car bogs at low RPM's no mattery what gear you are in or what speed. Once you get about 3/4 down on the gas pedal or the engine gets over 2200 RPM's, the car runs like a scaulded dog. The bogging is getting bad to the point where it is seriously hindering daily driving. Any suggestions?