Elevated RPM at speed in neutral

[rbattelle]

I've noticed that with the transmission in neutral and the truck coasting along at speeds above 10 MPH or so (such as when exiting the highway approaching a stop light) the engine runs at about 850 RPM, and sometimes will oscillate between 850 and 750 slowly until I depress the brake to come to a stop (at which point the engine drops to proper idle speed 750 RPM). Has anyone else noticed this? It's almost as if the engine computer knows the vehicle speed is still high and it's anticipating a shift into a lower gear so it keeps the RPM up a bit.

 

[Prairie Dog]

I've found that lots of vehicles do that. The first manual trans car I ever drove was a new 1977 Toyota celica - it did it too.

 

[Blakers]

Yea some of the old gas engines had a dashpot on the throttle stop that kept the rpm from dropping off too abruptly between shifts. It probably caused them to stall out.