91 volvo 240 stalling

my daughter has a 91 volvo 240 with a 4cyl and auto. roughly 100000 miles. it starts and runs fine but after driving it, if it is shut off for less than 30 min, then she tries to start it again, it stalls immediately. she can keep her foot on the gas slightly and drive it the distance of a parking lot, the car will run fine and not stall. i was curious if a tune up would fix this or if there is a smaller fix such as a sensor. thx for any help

My 91 did that for many years. Fresh spark plugs always seemed to help a little for a while.

Eventually the car got the inevitable slow water leak next to #3 cylinder, so after looking at the antifreeze stain down the side of my engine for a couple of years, I pulled the head and replaced the head gasket. While the head was off, I thoroughly cleaned all the vacuum ports and the EGR system, and I replaced the water temperature sensor (the rear, two wire sensor that talks to the fuel injection system). On a California engine, that sensor is impossible to access with the intake manifold in place. That was at about 250k miles and car never warm stalled again before I sold it at 300k miles. I attributed the fix to the replacement of that water temperature sensor.