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.

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 1,000 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!
  1. Home
  2. Questions
  3. Car starts very weakly after filling up with gas.

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: Oil leaking over two weeks

The engine may be leaking oil onto the undercarriage where you can't see it, but more likely, the engine is burning oil. This generally happens when either the valve guides or piston rings are worn. If there is too much...

Q: No fuel getting to the engine. Replaced fuel pump recently.

Other possible causes of your lack of fuel issue could be the fuel injectors or an electrical problem. If the fuel injector fuse(s) are blown due to a wiring issue, this may cause your problem. A clicking noise can be...

Q: Vehicle not starting after part replacement.

Hi, If you had all this work done to the engine and now when all is said and done, the engine will not start then I would say that something was not hooked up or not put together correctly. Your...

Related articles

Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
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...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...