Hi,
I am a newbie, just purchased a Volvo 244 1982. It has a rod knock, and I am disasembling the engine to see what else is not working properly. The previous owner told me that when at idle it surged. Upon removing the intake manifold I found a small hole 1/4 inch in diameter between the fuel metering unit and the large round opening where the air valve lives. It looks like someone has replaced the metering body and took something out of the hole (gouge marks around machined hole). The hole is now open to the atmosphere and allows air to enter into the airstream which is coming from the airvalve. What was that hole for? The car has a lambda sensor and cis. Thanks for any help. Alyn