Q: Which transmission solenoid would cause the trans to go slow when foot in gas and think it's in another gear then first?

Hi there. Typically reduced acceleration is caused by a worn out torque converter or obstructions of hydraulic fluid inside the transmission. The solenoid simply acts as an activation device, but does not impact the application of the transmission. You might want to have a professional mechanic complete a car is hard to accelerate inspection to help diagnose your problem.