2004 Yamaha f150 running rich plugs black . Leak down almost 0 on all 4 all 4 plugs black , no water in fuel . Have verified timing marks are perfect , injectors replaced , Vst cleaned and all filter replaced , t stat new , 40psi fuel 125deg at idle do have a code 29 intake pressure not sure why runs so rich , IAC iworking fine it seems . No other codes