Bad injector(s)...can car still run properly?
 

I've been trying to get my arms around why my car get's such poor MPG(9 city, 12 Hwy), and it's been suggested that my air flow sensor/metering unit is defective(runs rich), which of course is not small change to fix it.

Can the car run "normal" with faulty/leaky injectors, or would it be very noticeable.

Thanks!

Many things can cause poor fuel mileage. Most common is the aged WUR.
Here is a tune up list off the top of my head:
> Map AFR curve
> Verify WUR system/cold/warm/boost pressures
> Verify fuel flow from fuel head and at injectors is in spec
> Test fuel injectors for leaks, pattern
> Verify proper distributor function and timing.
> Inspect/mic air flow meter
> Verify both fuel pumps are getting 12.5V min and flow is in spec
These cars can run prety rich before performing so poorly you notice. Once all the above items are in spec the mileage and performance will increase.

9-12 is pretty normal for a modded 930.
Yes a CIS fuel injected 930's would run pretty normal with leaky injectors, CIS stands for 'Constant Injection System' so they spray/leak the whole time the car is running. The main symptom of leaky injectors is hard starting and rough running after starting.
The WUR, Warm Up Regulator, signals the fuel/air amount all the time not just in warm up and if it is off it can hurt mileage as stated earlier if to rich. If it is lean it will damage the engine.
The main culprit for poor mileage is usually the right foot of the driver :)