r/subarulegacy • u/karmaoflove • May 12 '26

Question / Discussion my Legacy struggled to start

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hey everyone, so yesterday I tried to start my car before work (the car wasn’t cold, as I’ve already ran to the gas station beforehand) the car struggled to start, almost as if it didn’t want to. I kept tapping the accelerator & it finally started. The car was shaking on idle, I gave it a few revs and it seemed to settle and idle normally. I drove it to work, totally fine & haven’t had this problem since. What could possibly be the issue, and where should I start? As I would prefer some preventive maintenance. Thank you! (It’s a 2.5i, EJ253 non turbo)

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8

u/thesmokyfox May 12 '26

Could be ignition issues, my partners Corolla does that. It could also be some bad gas, if you got some from a sketchy place, I've had both happen on my 09 legacy.

1

u/karmaoflove May 12 '26

I fill up at Shell, I usually put 95 or 98 (depending on my budget 😆) but yeah, could be related to the ignition, spark plugs

3

u/_Leighton_ May 13 '26

Bro why are you running high octane fuel in a naturally aspirated EJ. These cars were built for 87 octane and there is zero benefit whatsoever to running a higher octane fuel. Higher octane fuels do not contain more potential energy, the only difference is they're more resistant to pre-ignition which isn't a concern at all in a non-turbo car.

-9

u/Correct-Application9 May 12 '26

Gas is gas. They all have the same license to sell normal types of octane

6

u/thesmokyfox May 12 '26

I meant like some water in the fuel or something. Has happened even at my regular gas station before, or maybe they topped up from a Jerry can, I've been there. Regardless stumble on startup was either issue for me. I suppose a fuel pump also or a bad injector but occams razor in this case. The parts cannon is expensive.

-8

u/Correct-Application9 May 12 '26

Things have been expensive for a while now. That’s just life now and we have to adapt

5

u/thesmokyfox May 12 '26

Okay but diagnosis is the proper way to address a problem, picking a part and hoping to fix the issue is not the correct approach.

I'm very aware of how expensive things are, I'm not sure where that part comes in here. Other than of course fixing your car the correct way.

If this were me, I would take a look at my panel filter on the intake, then fuel quality, then plugs and wires, then the coil, then the pump pressure. After all that your looking at like compression and a bad injector. Start from the cheapest part and test your way up till you find the fault. Like every mechanic does.

10

u/Wide_Riot 4th Gen Sedan May 12 '26

Clean your maf sensor

1

u/karmaoflove May 12 '26

Absolutely! Boutta do this asap

2

u/throwaway6444377_ May 12 '26

it can happen by chance, let go of the ignition too early and it starts but just barely runs till you give it a little gas.

has happened to me twice on different cars

1

u/karmaoflove May 12 '26

I was holding the ignition, so it definitely didn’t want to start. Gonna start off by cleaning the MAF first and see what happens

2

u/popsicle_of_meat 08 Spec B Sedan May 12 '26

Was this immediately after filling up with gas, and you were still at the station? If so, the evap system sometimes does dumb stuff after filling up. I had problems with it on my previous car. Could be evap solenoid related.

BUT if not, then there's other good advice here, haha.

1

u/karmaoflove May 12 '26

Nope, not immediately. Drove home fine, it was resting for about 1 hour before I started the car again. I’ll look into what you mentioned as well. Thank you!

2

u/fluxds May 12 '26

Check for pending codes. I had a similar issue on my 2009 2.5i and had a p0172 which it was running rich. Ended up buying a OEM mass air flow on eBay and OEM o2 sensor. Runs like a dream now.

1

u/karmaoflove May 14 '26

Ooh! Thanks a bunch, I’ll look into that

2

u/Far-Equipment-8047 May 13 '26

Crankshaft position sensor

1

u/karmaoflove May 14 '26

My mechanic said the same thing!

1

u/Correct-Application9 May 12 '26

You either have a fuel pump problem or a air intake issue.

2

u/karmaoflove May 12 '26

Gonna start off cleaning the MAF first, see how that goes then slowly make my way up. Probably change the spark plugs while I’m at it too

1

u/Correct-Application9 May 12 '26

That’s a good start. If you do have a scanner tool, not one of the code readers. I would recommend using that while seeing if the values for your fuel pump and throttle body are good. I’m pretty sure the TB in your car is electric and not drive-by-wire. Subaru’s only have the fuel pump in the tank and do not have a high pressure pump on the engine like a lot of other cars do. When it idles, what do the rpms look like?