1990 Plymouth Acclaim 1990 Acclaim stalls without foot on g

I bought a 1990 Acclaim last week. Car worked fine for a while, but after sitting for just a few minutes with the interior light on (and possibly headlights, do not remember for sure). The car wouldn't start. It did start with a jump, but since then it stalls unless I keep the gas pedal down part way and the engine around 1000 RPM. Car will drive, but again, when I stop at a light or slow down for a turn, unless I keep the pedal down some, it will stall. Any ideas? Something a relatively car ignorant person can do?

Frrank