I'm at a loss here...Our MGB starts, idles properly and runs smoothly. THEN, when we reach a stop someplace, the idle won't drop below about 2000rpm. The only way to get it back to normal while at a stop is to hold the brake and ease the clutch out a little. Clutch back in and it idles properly until the next stop light. Carb linkage is not sticking and accelerator cable doesn't sppear to stick. We have an aftermarket electronic fuel pump putting out~theoretically~3psi but it never quits running. Any ideas here ?? Thanks.