I drive a 1988 Volvo 760 Gle. Ithas 130,000 miles. I was given the car by a family member when it had just around 100,000 miles. Since I have owned the car I have used redline fuel system cleaner every 3k. My question is that in the past year I was on vaction and didn'tdrive the car. It was driven maybe 10k. I recently got back and noticed the car seemed sluggish. So I got an oil change and threw in some redline. Now it seems the car has a slight sputter and going up hills the car dies. Never had an issue like this before. Could it be that the Redline loosened some crud up and it partially clogged the fuel filter or the fuel filter screen???