Sudden Deceleration - Throttle closes?

[Noblunts]

I've been driving the gen3 camry for a few days now and when I let off the gas, RPM drops very quickly. Its as if someone shut the throttle body instead of gradually closing it. With the cruise on it feels like hard engine braking just dropping 1 or 2 MPH.

Manually working the pedal at 45-55 feels pretty similar. RPM goes from 2k to like 1200 as soon as gas is released and speed drooops.

Am I correct to assume its the little diaphram near the main spring? Is that the throttle return or hold open? Acceleration and shifting seem fine.

[hill8570]

Seems likely to be the throttle damper (the part you mention). Fairly easy to test with a mityvac. Even without, you can get a pretty good go/no-go -- with the vac hose disconnected, your idle should bump up to around 2000 rpm (damper fully extended); with the vac hose connected at warm idle, you should be around 650 (damper pretty much fully retracted).