Transport Fuel problem?

We have a 91 transport 3.8 that died on us. No waarning, no gauge trouble. Stopped at a stop sign and it was like I turned off the key. Wouldn't turn over, seemed to be seized. Van sat for almost 2 years then we took it into the shop and got a 55k buick 3.8 that the shop installed. The install went smooth, only problems being a fuel line leak that they patched and the intake plenum issue (late I found to be a normal problem). I installed a new plenum and everything seemed to run fine. Started getting a grinding noise from engine, the a/c clutch was binding up. Over the weekend I pulled the compressor, cut the clutch out and reinstalled. There were some wires grounded to the coil-pack bolt. These apparently wern't wired securely and came loose. I put a good connector on. The ground wire from the coil pack, 3 black wires coming up from the main harness that included the a/c plugs, and a white wire as well. I wasn't sure what the white wire went to and assumed it couldn't be a ground so left it disconnected. The van had a starting issue before I did the a/c thing. It would have to be cranked a bit before it started. When I got in to start it, it ran right away. Seemed to idle rouglhy at first but smoothed out. It idled fine and at half throttle was fine, anything more and it would sputter. I replaced vacuum lines that looked bad and that seemed to help a little. Almost seems like I hear a small intake leak back behind the power steering. The van ran fine for short trips, after warming up 10-15 minutes it would start sputtering at idle and barely drive. At this point, we nursed it to work about 1/2 mile down the road and I got it to idle a bit after letting it sit and then it died and cranks but no start. I'm wondering if I have a fuel contamination problem and need to flush the line. I think they installed a new filter but that isn't 100% sure.