Welcome to a common problem ... just so you don't waste $/time on the same thing here's what I've done to no avail:
- new Autolite plugs
- new Magnecore wires (cured problem for a short time)
- new coil
- new DPFE sensor
I'm starting to think it's dirty injectors or a bad ground somewhere. I'll be replacing my injectors this week sometime - let's hope that's it.
