Ok so I have a 98 a4 with the 2.8 v6. It ran good till one day I was driving down the road and had to brake hard to not hit a car. (It's a 5 speed) when I went to accelerate again It starting breaking up and bogging down no matter what gear it was in. I tried down shifting but still running bad with no power. I drove it like this for a few weeks, no power, breaking up and stalling occasionally at idle. I changed the oil, spark plugs but nothing. I just changed the spark plug wires and it ran pretty good once I did but not even 2 miles into the test drive after changing the wires it make a weird sound at a higher rpm and completely stalled. It won't start at all now. Just turns over. It's getting fuel to the fuel rail from what I tested. Does anyone know what this problem could be? I'm going to test the coil packs next, than the fuel injectors. Really I don't know what it could be tho.

 

check codes to see what cylinders are misfiring and check those specific plug wires for spark. keep in mind on the 2.8L there are pairs on the pack. do a resistance check between the two coil towers for all 3 pairs. should be 3.6-4.4 ohms. someone chime in if i missed somethin, but this sounds like a coilpack. keep us posted. i would leave fuel injectors alone. if the ICM inside the coil is shot you will have to test the plug going into the coil. but we will get there if need be.