I have a Toyota Sx Carina, Model 1995, engine: 5E-EFI.

I just bought this used car. But when I am driving I am facing some problems.

When I drive in D mode the RPM (race) is not constant. It is just frequently changing (from 1000-800). And when it comes to 800 the entire dash board, steering and the seats start jerking. What can I do?

N.B. : I have tuned the car and checked the spark plug and filter. And those are all perfect.

  • Welcome to the site. Is this with the car at idle (in D with your foot on the brake)?
    – Zaid
    Aug 27 '15 at 6:37
  • When you say the spark plug is perfect, how was this determined. Aug 27 '15 at 12:00
  • It sounds like it's at idle due to the RPM range and it also sounds like the IAC valve which I'd recommend replacing first. What happens when you turn the AC on? Better or worse? Aug 27 '15 at 16:20

Assuming this problem is with the vehicle stationary and at idle (question states 800-1000 RPM), this usually happens due to one of the following reasons:

  • A leak in the air intake tract/manifold that allows unmetered air in

    One could detect the presence of leaks through a smoke test. Compressed air and soapy water works as well.

  • A faulty idle air control system

    This can be a bit more tricky to diagnose. Consider this option after eliminating the possibility of leaks.


Zaid is right, (all credits for his post) I just want to say that I've had the same problems a couple days ago, this can help alot:


It's not very expensive to repair and not difficult at all


  • If you include a link, please also include a summary of the content, as links can go 'stale' with time
    – Nick C
    Aug 28 '15 at 9:36

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.