Bean, A quick answer on Comp. Test...
1- Best to have engine warmed up
2- Pull coil hot wire (brown?) off. Terminal 15 I think. (The single wire.)
3- Pull the plugs
4- Have someone hold accellerator pedal to the floor (or contrive a way to hold the throttle open)
5- Proceed with the test
There will be no fuel pumped with ignition disabled (FI Relay requires pulses from coil negative in order to pick).

"CIS" means Constant Idle Speed, and is often mixed up with "CI", which stands for "Continuous Injection" aka "Mechanical" (which isn't really correct, I've been told, as mixture is fine-tuned by O2 sensor/electronics.
Idle speed (CIS) uses small stepper motor/valve to contol bypass air around the throttle plate. It's under the intake & has 2 hoses & 3 wires.
The thing on the right front (turbos only) houses air filter and fuel distributor, which measures air flow for basic mixture control. I'd suggest 2 Bentley books: Volvo 240 Service Manual (1st choice), and Bosch Fuel Injection & Engine Management. (Don't trust my memory!)
Good Luck,
Bruce Young