Q: Idling problems and difficult startup

asked by on July 25, 2016

My car has been idling poorly. It has difficulty staying up as well. I have to apply the gas and rev the engine up to get it to run. While idling, it would occasionally increase the RPM all of a sudden and stay at high RPM. This would keep the car running at the constant speed without me applying the gas. Also during idling, it happens that the RPMs decrease to 650 and it seems as if the car would turn off. So, I then put it in neutral to keep it running. I had the spark plugs replaced. Also the fuel pump relay is new. I changed the oil. What could be wrong?

There are many different items that can cause the vehicle to idle poorly. The most common would be the spark plugs and wires, MAF sensor, vacuum leak, IAC valve, exhaust leak, or oxygen sensor failure. I recommend having the vehicle checked by a professional before blindly replacing parts. A qualified technician, such as one from YourMechanic, will be able to diagnose the idling issue and perform any repairs required.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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

To shift into drive gear, have to rev engine

Hi there, thanks for writing in about your 1982 Ford F-100. The new modulators may be to blame if the parts are not exactly like the original one and made somewhat the same way. This can lead to improper performance....

Car doesn't move at all when iI engage the gear in both drive and reverse, rather shows W on the dashboard for gear position 2001 Volvo S80

Hi there - the "W" displayed on the instrument cluster means that "Winter mode" is selected. This means that 2nd or even 3rd gear starts are invoked (rather than 1st) in order to get away from a dead stop in...

Inconsistent RPM. It is too high majority of the time

Hi there. If a high idle is the concern a sticking idle air control valve or a vacuum leak could be the problem. Has anyone attempted an idle adjustment? If so, reset it back to the factory position. Listen around...

Related articles

How Can I Keep My Fuel System Clean?
Proper Proper maintenance of the fuel system is crucial for consistent long-term performance of a vehicle. The most easily clogged parts of the fuel system are the fuel injectors themselves. There are a number of ways this can happen: ...
How Often Should the Fuel System Be Inspected?
Without Without fuel, an internal combustion engine will not run. For this reason, parts used in the fuel system are built for durability and can stand up to years of near-constant use. Some parts, like the fuel filter, exist to...
The Importance of Warming Your Car Before Driving
Scandphoto / Shutterstock.com Many people feel that it’s important to warm a vehicle up before driving off. This has long been the dominant school of thought, dating from when cars had carburetors and many would not run...