Skip the auto shop - Our mechanics make house calls

Q: Car starts very weakly after filling up with gas.

asked by on

Recently I hit a curb in avoiding an accident, blowing the right front tire. After changing the tire, I took it in to the Subaru dealership to diagnose any problems, particularly the Check Engine light which had by now illuminated. After a few trips, replacing tires and so out, it was decided that my Engine light was the result of a bad engine fuel pressure solenoid. I had to wait on the part, so I drove it home. The following morning, I filled up, which is the first time I encountered the weak start up. The car seemed to be responding similar to a motorcycle starting cold without being choked. I took it back, and with the solenoid replaced, the light went out, and I drove home, only to find that the light illuminated again on the way home. The next day, they replaced another part in the same system, and now the light is gone. I was assured the weak start was caused by this faulty system, now replaced. However, now filling it up this morning, the issue remains unresolved.

My car has 138966 miles.
My car has an automatic transmission.

A: Hello and thank you for contacting YourMech...

Hello and thank you for contacting YourMechanic. Sometimes the gas cap vent tends to get stuck shut making the fuel system go into a vacuum. Check the gas cap for the seal to ensure that it is sealing. Make sure that you are filling the vehicle up before it hits 1/4 tank of gas. When it gets to about 1/4 tank, the fuel gets sloshed around with the junk and build up in the bottom of the tank. The pump could pick up the build up and clog the filter.

I recommend replacing the gas cap and seal first then rechecking the system. I also recommend replacing the fuel filter if your vehicle has an inline filter. The filter could be causing a restriction on the system preventing the engine from starting. If you are still having fuel issues with your vehicle, I recommend that you seek out help from a technician, like one from YourMechanic, to assist you with diagnosing your car’s starting issue.

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: Rattling on a 2005 Subaru Forester

Yes, the catalytic converters would often rattle. Catalytic converters look like mufflers but they are not. They have platinum inside these ceramic pieces and the hot air goes through them and burns hydrocarbon. What happens is, the ceramic parts start...

Q: Mustang started and then died

There can be a large variety of reasons as to why your Mustang is not starting. When you add to the equation that it has been sitting for a couple of years, it may mean your Mustang is facing multiple...

Q: I just had my tires changed and now my abs light is on

Your car is equipped with wheel speed sensors at each of the four wheels which monitor wheel speed while relaying this information constantly to the ABS and traction control system which are controlled by the car's ECU. When the ECU...

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 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...