Skip the auto shop - Our mechanics make house calls

Q: rough idle

asked by on

it doesnt want to idle when its first started when the motor is cold, then after it warms up it will idle it will idle but a rough idle and when im sitting still its loping, like its getting to much gas and i also smell gas. i have already changed the spark plugs and spark plug wires and the filter is good.
My car has an automatic transmission.

A: These engines had a bad problem of getting ...

These engines had a bad problem of getting excessive carbon build up on the valves that causes this problem. You may need to have the intake system cleaned out more than once using a combustion chamber cleaner. Be sure to clean the fuel injectors as well. Once this is done, the fuel pressure should be checked to make sure it is correct and not leaking. If it is, then it may be a defective pressure regulator. I’d suggest getting some assistance with this by having a certified technician, such as one from Yourmechanic, to help diagnose your rough idle and fix it accordingly.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 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!

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: Clutch messed up on my car keeping my truck from parking.

Hello. If the engine is not cranking that can be caused by a number of different reasons. If the truck is equipped with a manual transmission then you may have a failing clutch switch which doesn't allow the starter to...

Q: Car won't stop making noises and jerking .

The rough running circumstance you are describing is often a consequence of multiple faults in ignition, fuel, and air induction, not to mention the possibility of low or uneven cylinder compression. Just as a for instance, you could have uneven...

Q: What is the “All Seats” function about in the audio system?

It’s tough to give all passengers the right listening experience while you’re on the road. Different areas of the car experience different amounts of road and wind noise. What’s right for the driver might be very wrong for someone sitting...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...