I have a toyota vios 2003. When I accelerate my car(when driving at certain speed say 20km/h it accelerates lets say up to 60km/h but when I take my foot off from acceleration paddle rpm drops very quickly(~1000 which is normally the rpm when idle) and feels loosing the speed abruptly. I remember this was not like before. I recently replaced fuel filter and fuel pressure pump. Is this normal or indicates a problem?

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    Are you talking about when the vehicle is stationary or when it is driving? when in neutral & stationary this sounds like expected behavior, you increase throttle the engine revs up, you remove throttle the engine goes back to idle. What are you expecting, out of curiosity?
    – James T
    Aug 5, 2016 at 9:20
  • What you are describing is exactly what should happen, I expect you know what but simply haven't stated the problem completely. If you could expand a bit that would help
    – GdD
    Aug 5, 2016 at 12:37
  • Is this a manual or automatic transmission? @JamesTrotter He mentions losing speed, so I would assume it's while driving.
    – Yousend
    Aug 5, 2016 at 14:23
  • @JamesTrotter This is a auto transmission vehicle it happens when driving.
    – Michele1
    Aug 5, 2016 at 17:26
  • Maybe your calipers are sticking and when you let off the brake, the sticking caliper is slightly pressing the brake pad against the rotor? Have you changed brakes any lately? Can you look at your rotors and see if they are heat checked or have heat spots on them?
    – Facebook
    Aug 5, 2016 at 18:35

1 Answer 1


It appears to be throttle body calibration issue. I did a engine tuneup recently and cleaned up throttle body for carbon residue. After calibrating throttle body sudden rpm drops has not been observed so far at least in test drive..

  • Good information; glad you fixed it!!
    – Facebook
    Aug 7, 2016 at 22:56

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