Skip the auto shop - Our mechanics make house calls

Q: The car has trouble starting after gas tank is filled up

asked by on

The car has trouble starting after gas tank is filled up

My car has 52000 miles.
My car has a manual transmission.

Hi There, It sounds like you may have a problem with your evaporative emissions control system. Your car has a small purge valve called a purge solenoid in the Evaporative Emissions system that controls the venting of fumes from the fuel tank as these fumes build up inside, particularly when you are refueling the car with gas. The EVAP system prevents fuel vapors from the fuel tank from escaping into the atmosphere. The EVAP system collects and temporarily stores the fuel vapors in the charcoal canister. The charcoal canister is filled with activated carbon pellets that can absorb the fuel vapors. When the engine is running, the fuel vapors are purged from the canister and burned in the engine. The vent control valve (solenoid) controls the flow of outside air in and out of the charcoal canister. The vent valve is controlled by the engine computer (PCM). Normally the vent valve is open. It closes when the engine computer tests the EVAP system for leaks. If a leak in the EVAP system is detected, the Check Engine light will illuminate on the dash and the trouble code related to the problem will be stored in the engine computer. When an air leak is present in the EVAP system, the MAP sensor will not be able to determine the air density, and the MAF sensor will not be able to determine the volume of air, entering the engine correctly. This will lead to an over fueling situation or an under fueling situation depending on the size of the air leak and engine operating speeds and load. This may eventually lead to catalytic converter problems as well as misfiring problems. I would recommend having an expert from Your Mechanic 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: Will my car shut off when it's low on oil or coolant?

The signals you get in your car simply warn you to turn the engine off when the oil and coolant are too low, but will not shut the car off on it's own. When the oil pressure switch detects low...

Q: Car makes a single loud pop when first backing up or pulling foward. Sounds like s hammer.

You should have the lower control arm ball joints checked to see if they are loose. Also, check the sway bar link arms and sway bar bushings for wear or damage. An inspection of your suspension...

Q: Water was spilled in the trunk which soaked the car battery. Car won't start now. Does water destroy a car battery?

Hi, thanks for writing in about the concern with the BMW 320i. If the battery was submerged in water then it's completely possible for the battery to short out and die. Your friend will need to have the battery replaced....

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...
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.