Mg zs Idle isue and engine cut out

Hi folks can anyone suggest some fixes for me i have an mg zs 1.6 2006 and i was washing my car today

after i had washed it i noticed when i started it revs were fluttering and the car would keep cutting out i managed to get the car home

but now the rev counter wont work atol and the engine keeps cutting out unless i hold the throtle down a bit the car runs fine if i hold the revs just wont idle and rev counter isint showing revs can anyone help me out thanks

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