Anyone good with TBI?

[Syndrome]

I've got a 350 TBI out of a 87-91 G20 van in my 1970 GMC. I didn't install the motor, it was rebuilt and put in while the PO owned the truck. Though it was rebuilt he never got it to run correctly so he parked it and it sat for over 2 years.

When I got it I siphoned the tank out, put new gas in it, and siphoned it again. I cranked it over a few times, put a little bit of starting fluid in it and it started up. It idled pretty rough for a bit then settled down and I drove it about 50 feet. I stopped there to bleed the brakes and top off the tranny(it leaks at one of the seals).

I started it up to move it into my driveway and when I put it in gear it would die, at that point my battery died and it was dark so I left it for the next day.

I couldn't get it to start anymore after that. The fuel pump it had sounded terrible, and was rated for 125 psi max, which is much more than TBI needs, so I picked up one of these: Airtex inline electrical fuel pump, 10-14 PSI 35 GPH. I also got a inline fuel pressure gauge and I'm getting about 11.5 PSI, though the gauge is known to read slightly low.

I replaced the gaskets, o-rings, filters, regulator diaphragm, and regulator spring in the TBI.

Its got fuel coming out of the injectors, though it seems a little weaker than other TBI's that I've seen running. Its got spark, with new plugs, wires, distributor, and coolant temp sensor. I swapped the injectors for some that I got from a friend and they spray the same.

I've swapped out the ECM, Electronic Spark Controller, MAP sensor, the module under the distributor. They weren't new parts but stuff I pulled off of another vehicle, same results with any of the various parts installed.