Ford F-150

Ford, ecololine 150, 1997, 108100. I just purchased this van. I have noticed that from take off that it feels sluggish( almost like it is under a load). But after you get going then it is fine. Then today the check engine light came on. Now at speeds between 55-70 it almost feels like it surges. The dealer said that they changed the spark plugs because it needed a tune up. Now they are saying that the plugs may not have been changed. Where do I start to look for the problem.
September 9, 2006.

If it were me I would change the plugs, wires, cap, and rotor, and also the fuel filter that way you got all bases covered. A van is a pain to work on anyway and there hard to work on. So if you do all this the first time you have to keep pulling that cover inside to fix it.(NOS) 8)

Sep 13, 2006.