Hi guys. I have had volvos for the past 23 years. My son has an 84 240 sedan. The car runs decently until it finds a hill. Then it knocks and pings until it loses power and over heats. We gave it a tune-up, fixed any vacuum leaks and will replace an old O2 sensor tomorrow just for fun. Anyone have any suggestions? What about a knock sensor?

 

check the timing advance with a strobe light?

which ignition system does that 84 have? is that the 'chrysler' ignition control unit on the right front fender, with the vacuum diaphragm right on the ICU ?

 

Im not sure which system it is. I've tried to figure out how to adjust the timing. But dont know how. Distributor can't be moved. I assumed it was electronic since I can't find a vacuum advance anywhere.

 

on the right fender wall, behind the right side headlight, is there a flat electroncis module, which has a vacuum bellow on the bottom forward facing side ? it looks something like this, but turned 90 degrees counterclockwise...

 

Thanks! I found it and was able to adjust it. Adj. bolt was hidden under wires behind distributor. Seems to be working well now.