It will take 2 people to check this, but perhaps your accelerator linkage is not adjusted correctly. Perhaps the linkage is closing the microswitch in the engine compartment before you are at wide open throttle. Shine a light on the switch while someone steps on the accelerator and make note that the microswitch should not be closed unless the pedal is all the way to the floor.
If the throttle linkage is adjusted correctly, perhaps the switch is sticking. I would think a spray of electrical contact cleaner should help.
Good Luck. It is too hot already to start having A/C problems!

__________________
John
1986 300sdl
1985 380se