1990 Volvo 740

Helllo,

i have a 1990 volvo 740 wagon, which I just bought. For the past month we've been having this terribly annoying issue. The car will run like a top most of the time; very smooth, great acceleration, just great. At least once a week though, after driving the car for a while, when it comes to a stop it will stall out when given gas. It almost feels like it has bad gas in it. It will turn over, but have a hard time catching, once it does catch it runs like it's out of gas; very choppy. Once it's parked and sits for a bit, it starts right up. The other part of this issue is sometimes it won't start up from the get go. I'll leave it for a bit and then it starts and runs like nothing happened. There aren't any warning lights on, so I don't know where else to go.

so far we've replaced the fuel pump relay, radio suppression relay, air filter, throttle position sensor, starter and fixed a vacuum leak. The person that owned it before me put in a new timing belt and sparg plugs recently.

does anyone have any clues as to what the issue might be?

thanks for taking the time to read this.

meghan