By depressing the accelerator pedal, you're opening the throttle plate which allows air to enter, so it would seem that your basic parameters(air/fuel) are out of sync. You're having to provide it with additional air artifically to start-up correctly.
1991 300-SEL - Model 126
M103 - SOHC
James Madison - Oppressors can tyrannize only when they achieve a standing army, an enslaved press, and a disarmed populace.
Liberty Firearms Training - After years of trying to regulate California criminals with a never ending stream of gun control laws they have still not given up with the belief that if they make something a crime that criminals will miraculously start obeying the law.