hi there I have a r32 gts, my problem is it drives fine but idles like its got lumpy cams and wont start on its own without pumping the gas while im turning it over. but I can unplug the afm and it starts first start but idles high then low because its unplugged. when its running unplugged you can plug the afm back in and it dies iv only changed fuel filter, plugs,coils,cleaned throttle body out etc. any help would be appreciated. cheers