hi i have just fitted my head back on car after belt slipped bending every valve anyway rebuilt running but missing a bit its ok wen i apply gas but on tick over it goes up and down help plz

 

As in the revs rise and fall?

If so sounds like a sensor.. Idle control valve (under the inlet on the front) is a common fault on focus's. Take it out and clean it out or replace (they are about £20 i think on ebay)

 

hi thanks for reply will have a go at that

 

Oviously I'm assuming it's been built right eg timing and what not.

 

hi yes timming was set right with the tools for it.the engine starts first time and wen it revs above 1100 it does not mis, the sensers were ok before rebuild,the head was skimmed all valves replaced and 3 guides 4 shims new belt tenisoner
chris

 

Most likely a air leak, especially as you have rebuilt spray WD40 around the inlet manifold with engine running and see if this changes it, if so then there is a sealing problem. If it is being raised by the ISCV then it is being told to do so.

Martin