over reving on 206 1.4hdi

[davebowring]

just recently (and only occasionally at present) when i change gear the engine revs from say 2000 to 3500 then drops back
any suggestions please

[dm1982]

the hdi engines are notable for engine management problems, ie sensors needing replaced fairly regularly, have it put on a dignostic scanner. my money is on either the fuel pressure sensor on the fuel rail or the fuel pressure sensor on the fuel pump. there are a few other bits and bobs that go also. more uncommon one is the scavenger pump in the fuel tank packs up, or the high pressure fuel pump itself goes, you will know this however as when you change the fuel pump the bowl will be full of shavings and shrapnel from the pump breaking up. as i say needs put on a dignostic scanner to find out for def