Fuel gets in from exactly 2 places...
1. The cold start valve.
2. The injectors.
Most likely, you have something stuck open. Alternatively, you have a wiring problem.
Tools-wise, you have to invest in
1. 2 fuel line cut-off clamps. About 6$ at the nearest pep boys.
2. A pressure guage that will read up to 40psi. About 20$. Be sure it has (or be sure to also buy) the appropriate fittings to handle 5/16" fuel line.
3. A multimeter. If possible, the fancy digital automotive one from sears. I like that model. It's also available from JC Whitney.
Now that the weather is warm (at least here it is), disconnect the fuel line from the cold start valve and put the fuel pressure guage in its place. Turn the key to activate the pump (no, don't start the car) and then turn it back off. The pressure should hit 32psi the instant you hit the key, and it should stay there for a while.
If the pressure drops "quickly" (as in less that 30 minutes), the next step is to block the return line with one of the clamps (the return line is the one that comes off the damper). If it still drops quickly, use the other clamp on the other line.
If the pressure STILL drops, you have a leaky injector.
The problem may be electrical. For that, you need the dianosis procedures in "the book" (engine manual).
Long ago, I prepared a .zip file with scanned pages from several print sources. I send this file to anybody in your shoes. Send me an email (email@example.com) and I'll reply with the file attached.
Your last shot is to start swapping parts. That's expensive and will not get you far.