Some surging in the RPM's and my exaust it spittin out a black substance on my 1989 5.8 when i start it. I came to the conclusion that the EGR must be bad. Cleaned it and put back in, the surging isnt as bad but it is still spitting out the black stuff. When im parked somewhat on an incline thats when it seems to spit out the most, but when its level there is no substace coming out at all. When to autozone and they said they dont have a machine to diagnos my car because it has to be a 96+ The check engine light comes on everynow and then, mostly after about 30min or driving and the surging in the rpms starts. Does any1 know what it might be?