Q: When I start my car it the idle is very jumpy and the car feels like it wants to die

asked by on

When I start my car it jumps from 2000 RPMs all the way down to bear lyrics none then almost dies jumps back up to like a thousand then back down and it just keeps doing that

There are several possible causes for the idle to fluctuate like this. The most common causes are a faulty/dirty mass airflow sensor, a vacuum leak, an oxygen sensor that is reading incorrectly, or an idle air control motor that is unable to react quickly enough.

The most effective way to diagnose this situation is with a diagnostic scanner that can relay the data stream from the mentioned components in real time and compare that data to the acceptable parameters set by the manufacturer for each component.

Alternatively, you can perform physical inspections on most of the components, it just takes more time and knowledge. You can take a look at the vacuum hoses to see if there are any that have come unplugged or if the hoses have dry rotted and cracked. You will normally hear a "whistling" type sound from a vacuum leak.

You can also remove the idle speed control motor to see if there is a build up of carbon, which will keep it from being able to control the idle speed quickly enough to maintain a steady idle. There are several other possible causes for the idle to fluctuate, and if you need some help identifying the problem, feel free to contact YourMechanic to help you diagnose the rough idle and proceed with repair.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1,000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!
  1. Home
  2. Questions
  3. When I start my car it the idle is very jumpy and the car feels like it wants to die

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: I am having trouble starting my 2007 Dodge Charger and it does not have good acceleration

Hello. There are a lot of things that can cause this on your vehicle. I would usually start by scanning the computer for any codes. If there are codes set it can help to find the issue. If there are...

Q: Vehicle jammed in gear number 3 and "N" neutral light is continuously flashing. Reverse and park functioning properly.

This is likely not good news - since it appears that your transmission is in "limp" mode. Try disconnecting the battery, waiting 10 minutes or so, re-installing the battery, then driving it for 20-30 minutes so the transmission can reset...

Q: When I first put refrigerant in my car the ac was really cold after 2 days its still cool but not as cold is this normal?

It is possible that since you had a leaking O-ring, not only did the refrigerant leak out, but the outside atmosphere contaminated the receiver/dryer in your A/C system. The job of the receiver/dryer is to absorb any moisture and contamination...

Related articles

Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...