Car slow to start Subaru inpreza

Hello all,

On to the next project! We have a Subaru Impreza 2014 hatchback sport limited. It is slow to start after sitting for a day or 2 and what I mean is it takes longer to finally fire the engine up. Like 3-5 seconds. Internal lights don’t dim or flicker either.

I’ve replaced the battery, oil and spark plugs. I don’t think it’s the fuel pump cause I’ve tried the turn the key to the on position for a few seconds before trying to turn it over. It still happens.

The negative terminal on the battery has corrosion. I cleaned it but maybe the internal wire corroded too? I was going to try some voltage tests on the starter.

Any other thoughts or things I can give it a shot?

Try that 3-4 times instead of just once. If it fires right up you have a failing check valve in the fuel pump or a dirty and leaking fuel injector.


Okay I’ll give it a shot. I was going to pick up a fuel pressure test gauge from my auto part store. Hook it up and leave it for a few days to see if pressure decrease. Good idea to try?

The fuel pressure is going to decrease as the vehicle sits which is normal.

How quickly it deceases indicates if there’s a problem or not.

Residual Fuel Pressure Test
When the pump is turned off or stops running, the system should hold residual pressure for several minutes (look up the specs to see how much pressure drop is allowed over a given period of time). If pressure drops quickly, the vehicle may have a leaky fuel line, a leaky fuel pump check valve, a leaky fuel pressure regulator or one or more leaky fuel injectors. Low residual fuel pressure can cause hard starting and vapor lock during hot weather.


1 Like

Yes, good idea.

1 Like

If doing the “key dance” before turning the key all the way to Start does the trick, repairs are optional - if all users know the dance. My 1999 Honda has needed it a few times, especially in cool weather with low fuel in the tank.

1 Like

I did the “key dance” today after the car sat for 2 days. It would’ve typically done it after sitting that long. Fired right up after on/off 4 times.

1 Like

It fired up after 3/4 on/off today. It had sat for 2 days. To fix what you mention, is it easiest to replace the entire pump? (Or maybe that’s required?)

Yes the pump needs to be replaced. Or you could just live with it.

:+1:t3: I’m going to go with live with it. Thanks for all the help!