Pontiac Montana won't start, sputtering

So last week my van sputtered, wouldn't start, I figured it was out of gas. Put gas in it & it worked. Now exactly a week later at a traffic light the van starts sputtering and stalls out. Everything shuts off. I can't get it started. I left it sit, my husband came wiggled the coil pack wires, then it started up & sputtering lessens as I pump the gas. I drove it a block & it completely shut down again. It's had the check engine light and abs lights on for a year, ran fine. It tries to start, but won't turn over. The battery light comes on, but goes right out. We're guessing coil packs, but I don't know how to figure out which one is bad. It's got over 200,000 miles on it and can't afford anything new. Any help as to where/how to trouble shoot would be so appreciated!! Thanks in advance!