I have a 90 300SEL and this spring when I got her from storage she started right up and ran smooth as glass. I let it idle for 10 minutes or so and when I stepped on the gas she stalled and would not start again. I let it sit for an hour and tried again, started right up, again when I stepped on fuel pedal it stalled. I cranked her over and after awhile it would go but same issue. I have put fresh high test in the tank and it still has the same symptoms. So any ideas? Someone suggested cold start sensor, I don't know run perfect when I put it away. It has about 120,000 klm or 75,000 miles.