If fuel is getting to the metering unit then you have fuel... If you disconnect the pipe to the metering unit and turn on ignition to prime the system does fuel blast out?(Obviously have the line pointing into a container - use basic safety etc etc etc)

If so then you have enough fuel to at least prime the injectors.. but without a tool to measure pressure you may as well just start guessing...
Even a ebay cheapy gauge could be plumbed into that line temporarily for a couple of quid to get an idea (doesnt need to be 100% accurate just give a "good" idea)