when Memphis steals Elenor he uses a jimmy to start it up,during the chase,he's in a alley and the car stalls.when he tries to start it keys are in it.
A jimmy is used to open a car door (slim-jim), which he still didn't use or even carry for that car. What he used was a tension wrench and a lock pick to turn the ignition. After the first time all that is needed to turn the ignition is the wrench as long as it's not turned all the way to the lock position.