It's been a looooong time since I did any injection work. I think you have SEFI One injector per cylinder with a firing circuit for each injector individually. Results in better emissions and more power. The first thing to check is for fuel pressure in the main furl rail. You must use a pressure gauge, just having fuel present isn't enough. Fuel Pressure is approximately 45 psi. There should be a port to check pressure in the main fuel rail, it looks like the bottom of a T with a bolt in it.
An additional injector for added fuel during cold starts is often present.( You can also check pressure where the fuel line goes to this injector)
There is probably a relay to run the fuel pump when you cycle the ignition to "on".Hook up your pressure gauge and turn the key on a couple of times.
I would also suggest changing the fuel filter,if it hasn't been done already, before you even bother with the pressure check.
If you're going to fix this yourself you MUST have a repair manual. This should be want you want ( I don't guarantee it, do your own homework) I don't think it's still in print, but there seems to be a lot of used ones out there http://www.amazon.com/Mitchells-Elec...390760&sr=1-10
I used to work on all kinds of fuel injection both foreign and domestic and in ALL systems, fuel PRESSURE is one of the most important things to check. It's not impossible to fix with some study. You do need to know exactly which system you have and a reasonable understanding of how it works along with, the proper manuals.
If all else fails you could get a manifold and carburetor from a big block Chev, but the injection will give better mileage if you can get it going.