Okay, my wife called me today and said that her van was missing and jerking real bad and would not hardly go over 25 MPH or so but there was no engine light on. I left work to come home and she called me on the way and said that when she got home that smoke was coming from under the van around the front and there was a funny smell. When I got home an hour later I looked everything over but did not see anything obvious so I tried to start it and let it idle, but it would barely run and seemed to be backfiring through the exhaust. I did plugs, wires, cap and rotor approx 3 months ago but I looked under cap anyway. I didn't see anything obvious there so I checked mass air flow meter in the air intake tube and it was clean. I checked for good voltage at battery then tried to start it again. It seemed to idle better than when she got home and everything was hot and better than the first time I started it. I looked it over some more and tried to drive it down the road but it still missed pretty violently. When I came back it was just barely running and missing BAD! I had the air filter out of it and it was still back firing through the exhaust and shaking the whole exhaust system when it did. Anyone got any ideas? Fuel pump, fuel filter, distributor? Thanks for any help! Right now I have no transportation for my wife to get kids to school etc!