sorry lads just want to check somthing having bad idel probs when warm reving at 2500-4000 revs tryed disconecting plug but dose not do anything just carries on playing up!! so i got anouther as old one looked shaged!! Its the red top engine and the capp was grey and the new one is a red cap is this right??

thanks jamie

 

dont think it matters mate,seen a few with a red cap about lately

 

Would think if you've disconnected the plug from the ISCV and its made no difference its not that at fault

Sounds like throttle cable sticking or throttle butterfly sticking in throttle body for revs to be that high

Or base idle screw dropped out of throttle body is a possibility

 

what enigne

 

thanks lads Ill check the throttle body