I had my Z (76 280) out the other day and I noticed it has a lumpy idle. It has a stock cam, and the engine has never been rebuilt. It only has intake and exhaust. I realise the engine is tired, and it will be rebuilt this winter. I wouldn't mind it being rough due to the cam, but this feels different. It's not like an evenly timed roughness, it sort of shudders noticeably at odd intervals but the rpms stay dead even at around 900 and it doesn't make any noise.
What could be causing this?
What could be causing this?
