Testing EFI injectors

[Vic Norman]

I'm working on a Bosch L-Jetronic (EFI) equipped car that has been sitting
unused for a couple of years. Initial no-start diagnosis was no fuel
pressure. Cleaned out the gas tank and replaced the fuel pump and filter.
Now I have good fuel pressure. When I crank the engine it fires for a few
seconds and then dies - presumably the cold start valve doing its thing. The
obvious diagnosis is that the injectors are gummed up but how do I test
them? By the time I have got the injectors out of the car I have pretty much
torn the intake system to pieces so I can't simply crank the engine and look
at the injector output. I hate to spend several hundred dollars on new
injectors and then find out that they weren't the problem. Is it possible to
dunk the injectors in carb cleaner or some such to clean them?
Also -  is it possible to monitor the signal to the injectors with a basic
voltmeter (I don't have an oscilloscope) and if so, what sort of values
would I expect to see?
Thanks
Vic Norman  1996 A4 2.8 1989 Alfa Spuder Veloce