Engine Performance problem
1985 GMC Safari 6 cyl Two Wheel Drive Automatic 153000 miles
I'm working on a 1985 4.3 V6, The firing order is right, the timing is set, plugs are firing properly. This thing starts excellent, however when I drive it and it gets to about 20 MPH, it falls on its face. At 20 MPH it starts to spit and sputter and backfire. Is it loading up? Or is the distributer bad? I don't understand, I'm sure its something simple.