Guys,

My driving habbit is to put the gear in neutral when I know the car doesn't need power, so I can save some gas and reduce the exhaust (well, I believe it may slow down the global greenhouse effect a little bit). Like when I am about to exit the highway, I put the gear in neutral so the car slides thru. I have done this for more more than 20 years and never experience any problems on the engine or transmission.

Normally when I go in neutral, the engine rpm drops immediately to idle. But for my 88 camry, the engine always roars up to about 3500 rpm for about 2 seconds then drops to idle. Few times it drops immediately.

Does anyone know anything about it? Could it be the fuel pressure?

probally just a sticky throttle linkage or frayed cable.
Spray some rp7 onto the throttle linkage that joins to the side of the throttle body, you may even want to remove it.
Cheers Steve