Skip the auto shop - Our mechanics make house calls

Q: Trouble Starting, and sometimes doesn't start at all - Dies at idle from time to time.

asked by on

To start off, I just cleaned out the idle air control valve today and it seems to have made my car be able to easily start and run fine. There was only one time after doing that where it couldn't start right away, which may be due to getting throttle body cleaner in the system. I've had problems before this where it would crank but wouldn't start, and then at times it would start but have very low idle that I had to give gas to in order to keep it going. Before cleaning the IAC valve, it had codes P0171, P0335, P0340, and P0446. I am curious if any of these codes would be linked with my cars symptoms. Again, it seems to be running fine now, but there have been plenty of times where it seems to be fine, and then it will randomly not start after being left for a while. Before cleaning the IAC valve, it would idle around 500, and now it's between 650 and 750 after it's been running for a while. Mainly curious if those codes when stringed together can pinpoint a problem area.

My car has 110000 miles.
My car has an automatic transmission.

A: Hello. Cleaning the throttle body and idle ...

Hello. Cleaning the throttle body and idle valve may have been needed, but the intermittent starting and dying symptom can be the camshaft and crankshaft sensors. These are the codes P0335 and P0340. The code P0446 can be from the purge control solenoid malfunction but would recommend the other sensors repaired first. The code P0171 is the system running lean and can be from a vacuum leak or from the dirty throttle body and idle valve sticking (you may have fixed this code). If you want to have this problem scoped out more thoroughly, a certified technician from YourMechanic can come to your home or office to diagnose the starting issue and pinpoint what needs repair.

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・Save up to 30%

Get a quote

What others are asking

Q: Where is the Coolant Temperature Sensor located?

Coolant temperature sensor is located at the upper radiator hose where it connects to the engine. Should be a green plug connector just to the left of the hose.

Q: Startup issus, error codes

Those codes: P0170, P0173, and P0335 are indicating that the airflow coming in that is read by the MAF sensor to set up fuel injection timing does not match what the oxygen sensors are reading based on the exhaust sample....

Q: Engine light coming on

Hello. Code P0446 comes up due to a problem with the EVAP emissions vent system. This system collects evaporating fuel so that it does not get released into the atmosphere. The code almost always means that the vent valve has...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
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.