It's a 97' sunfire 4 cyl that at idle almost jumps from the engine bay with the shaking/misfire.. When we apply the trottle it studders then races sometimes smooth and sometimes rough until at about 1/2 trottle and then it seems to starve of fuel or justs bogs out.. This sarted with a little miss and now it will hardly stay running.. We've changed the plugs,wires,two coils,tried 3 modules,and a fuel filter with no change in the problem.. The engine light is not coming on and we can't seem to find a vacuum leak.. Anyone seen this before?