Help! my Merc C180 built 96 in South Africa with 460,000 km on, has got a problem somewhere in the fuel sensor: it takes almost 7-8 seconds to slow down from 3,000 rmp to 1000 rpm, and normally it doesn?t go lower than 1,100 rpm. Is it a sensor that I can just buy and replace without special settings? it?s not the spring outside the engine. I would be extremely grateful for an answer