Hello all, I just bought a 1989 volvo wagon and it seems that it has a problem that the previous owner did not mention. I first noticed this problem while driving, but it happens when I am parked in neutral as well, so I am assuming its not the transmission. The symptom is as follows.

-the car is parked in neutral (its a standard).
-I press the accelerator down a bit.
-the car begins to idle higher then it looses power, then goes back to idleing then looses power, and back and forth.
-its as if I am pressing the accelerator and releasing (like reving the engine), as in Power-No Power-Power-No Power. But I am holding the accelerator in the same position the whole time. I actually made a little movie of it that I can send or even post here.
-first I took of the distributor cap and cleaned it all out, then used an erasor (as per a mechanic) to get rid of any traces.
-this worked for a while, then the same thing.
-got a new distributor cap and wires installed ($180).
-good for one day and then, SAME THING AGAIN!
-the only thing I noticed is that at night (cooler) the car did not have this symptom, but during the day (hot NYC august sun) the car stops working.

any clues would be great. I don't really want to go back to that garage, cause I think the overcharged me. and Phil at VolvoLand (the nearest garage recommeded on this site) is on vacation for 2 weeks. I don't want to take it to just anyone if I can avoid it. any help?? thanks Dag.