my car jerks and my idle surges?

2007 KIA SPECTRA
107,970 MILES • 2.0L • 4 CYL • 2WD • AUTOMATIC
Avatar
JAS0822
  • MEMBER
  • 74 POSTS
I finally got a new car, and something started happening today. When I’m driving it does fine, but when I stop at a light or a stop sign, my car jerks and my idle surges and like bounces up and down. Someone tested my throttle position sensor, could that be it? They unplugged it while running in park and my idle didn’t change at all. Thanks in advance.
Mar 2, 2023 at 6:21 PM
Advertisement
Avatar
STRAILER
  • CERTIFIED EXPERT
  • 53,872 POSTS
Yes, the TPS can cause that, but we should run the codes to see what comes up. also, I have seen a dirty throttle bore or a vacuum leak cause this issue. so, let's go over these guides to help us fix the problem:

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Use this guide when the engine is cold only:

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

This guide to help service the throttle body:

https://www.2carpros.com/articles/throttle-actuator-service

Please go over these guides and report back.




Mar 3, 2023 at 10:44 AM
Avatar
JAS0822
  • MEMBER
  • 74 POSTS
So, there are no codes, and I just replaced the TPS because it wasn’t too much money. I noticed that the cold start RPMs changed. Before when I started my car on a cold start it idled at about 2000 rpm’s and now on a cold start it’s between 1,000 and 1,500 RPMs. I’m going to drive it tomorrow and see what that does.
Mar 3, 2023 at 4:46 PM
Advertisement
Avatar
STRAILER
  • CERTIFIED EXPERT
  • 53,872 POSTS
It could just need to relearn which can be done by just driving it. Here is some information on the TPS sensor in the images below. Please let us know what happens.
Images (Click to enlarge)
Attached Media
Attached Media
Attached Media
Mar 4, 2023 at 11:17 AM