Skip the auto shop - Our mechanics make house calls

Q: I need help finding what's wrong with my car

asked by on

You have to drive it like a 5 speed and it's an automatic you have to keep your foot on the brake and the gas at a complete stop so it won't shut off I'm not sure what's wrong with it. It has a rebuild Motor in it I need to fix it
My car has an automatic transmission.

Hi There, What you are describing sounds like a dirty or failing idle air control valve. The idle air control valve monitors the air intake as it is mixed with fuel prior to being injected into the engine at low speeds and at idle. This valve is controlled by the vehicle’s computer and will adjust idle speed based upon other measurements such as engine temperature, intake air temperature and electrical system load or voltage. This is also an important function when starting the motor as it allows the motor to run and idle on it’s own once the motor fires. When you accelerate, the engine RPM increases, and as you let off the gas, the RPM slowly returns to the normal idling speed with the help of the idle air control valve making the transition from a higher RPM back down to idle speed while adjusting the air/fuel ratio constantly to allow this to happen smoothly. When the engine RPM drops below the normal range of about ~800 RPM, 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 inspect your vehicle.

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: Found one black pipe detached when I opened the hood.

Hi there. The black pipe on your engine is the air intake tube. There are two different tubes. On tube goes to the air box where the engine air filter sits in. The other tube goes to a resonating chamber...

Q: Truck will start and then die down. Then sometimes it won't start at all, only turn over

Hi there. In many cases, a hard starting issue is caused by a fuel system or ignition system failure. When the starting is inconsistent; it tends to be fuel related. The best way to begin any diagnostic process it to...

Q: Car won't go into gear

Hi. This is a common issue and a sign of a worn clutch. The clutch along with some other components like the slave cylinder, pressure plate, throwout bearing, and pilot bearing will need to be replaced. The flywheel should be...

Related articles

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...
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...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.