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・Fair and transparent pricing

Get a quote

What others are asking

Q: white smoke oil leak engine light on

Hi there, thanks for writing in about your 2004 Toyota Sienna. It is very possible that there is an oil leak somewhere that is allowing the engine to burn the oil. Without further detail, it would be tough to say...

Q: My speedometer is going back and fourth and drops to zero while driving but, my rpm gauge is fine.

Hello. The crankshaft position sensor will not cause a fluctuation in the speedometer gauge. It can affect the rpm gauge, but not the speedometer. If the speedometer is acting like this then most of the time this is caused by...

Q: evap

Restriction in the EVAP vent or purge hoses can also cause this code. A restricted EVAP canister will also set P0446. A smoke test can find restricted canister. I suggest having a mechanic come out and diagnose your Check Engine...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
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...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...