Skip the auto shop - Our mechanics make house calls

Q: Rough idle and engine stalls out.

asked by on

engine start when sparying intake clearing in air intake manifold. spark plugs are filed out ,tips are black

My car has 190000 miles.
My car has an automatic transmission.

This suggests a rich fuel condition as evidenced by the black fouled out spark plugs. This can happen for a couple of reasons such as faulty or leaking fuel injectors, or a faulty or dirty idle air control valve.

The idle air control valve reads the air intake as it is mixed with fuel prior to being injected into the engine at low speeds and at idle. As this valve is controlled by the vehicle’s computer, it will adjust idle speed based upon other measurements such as engine temperature, intake air temperature and electrical system load or voltage. When you accelerate, the engine RPM increases, and as you let off the gas, the RPM slowly returns to the normal idling speed. When the engine RPM drops below the normal range of 750-800 RPM (for most cars), this often times will cause the engine to stall indicating a dirty or faulty idle air control valve. I would recommend having an expert from YourMechanic come to your location to diagnose and repair your idle air control valve.

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

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: What is the brightest bulb on the market for my 2006 Toyota Tacoma? I want my lights to be brighter.

One thing that you did not clarify was which bulbs you wanted to be brighter. I am assuming that you want the headlamps to be brighter. If you want brighter headlamps, you can choose a brighter bulb like a silver...

Q: Hyundai santa fe 2006 has trouble starting, rough idle and hesitation

A rough idle may be caused by many different things such as low fuel pressure, low voltage to the fuel injectors, dirty fuel injectors, a vacuum leak, a faulty Oxygen sensor or a dirty or failing idle air control valve....

Q: Can you jump a car still after engine blown?

when you say the engine is blown there are different levels of a blown engine. If your engine is seized then it cannot be jumped since the engine will not turn. If you have a blown head gasket and engine...

Related articles

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...
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...
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...