Originally Posted by
Knuckles84
I've just been through this same problem
Turned out to be a combo of cleaning out the iscv and replacing all the inlet manifold gaskets. They were all perished being on there since 1988.
Air leak on inlet creates surging when cold. Once warmed up it stopped surging but sat at 1200 rpm
Pulled the iscv last night and it was clean washed it out any way with a bit of clutch cleaner,
When doing this i noticed that if i put some in the end it would leek out through the two slots in the sides, should this be air tight.
Its a brand new engine so gaskets should be fine saying that i have had the inlet cover off so may be it didn't seal back up when i re fitted it.