My son's Malibu will occasionally just not go when hitting the gas. It is occasional which makes it frustrating to demonstrate - it's never happened to me while driving for example and I didnt fully understand it to even ask.

Anyway, it only happens after starting the car and initial motion. It is not, I dont think, transmission. Fuel system is just not getting signal to increase RPM.

Once the car is going it never happens again while driving. It is only after the initial startup.

Amy help me suggestions welcome.

Could it be something in the shift linkage or shifter? Only happening when shifted into D initially? When your son tries to take off, do the RPM's go up or does it do nothing?