Fast Idle on Mercury 40 EFi?

[ISLANDRIBBER]

Hi Guys,

My Mercury 40 4 Stroke EFi has developed a fast idle (1400rpm instead of 800rpm).
It also runs slightly lumpy but seems fine at higher revs. Looked for air leaks into the manifold, checked the resistance of the temp sensor in comparison with workshop manual but all ok and the plugs look fine.

Being an EFi engine I thought the idle was electronically controlled to keep it in spec?

Any thoughts appreciated.

Al