Suddenly losing acceleration, now it won't start :D

About six months back I bought this 2003 Subaru Impreza with the goal of tuning and eventually doing some basic and aesthetic mods. The previous owner of the car replaced all the main important components (Heads, timing, etc.) I expected that because it is 20 years old Id run into a lot of issues, but ones that I could manage to fix up on my own. Ive been into cars for years, but haven’t had as much hands-on experience as I would hope. Anyways, I still expected to be able to keep this car going. I have had no major issues with the car except: poor brakes (front ones a just replaced, have the parts for rear) and CV joints (plus a torn boot), dirty air filter, and some minor fluid leaks, which I was able to fix. About two days ago I was driving 25mph, at most, and my acceleration completely ended. I would press the gas, but there was NO NOISE or movement. The engine did not sputter, the car did not jerk. I believe all my lights were still on as well. No noise, no sudden movement, just completely stopped accelerating. I turned the car off and tried to turn it back on to see what would happen and it wouldn’t turn over. I was able to get my car to the side of the road. I got a friend to come try and jump me even though I didn’t think my battery was the issue. Obviously that did not work. The strange part is that it sounds like all power is there, it simply won’t turn over. So I got it towed back to my place.

My dilemma is that I am almost completely snowed in, and so is my car (don’t have a garage). So, I unfortunately can’t even look at the damn thing. I do not have access to an OBD scanner either. Still waiting on the one I ordered. On top of that, I didn’t check my fuse box enough either. I wish its something stupid like my air filter. However, I suspect it’s my fuel pump failing, just because it was so sudden with no previous symptoms. I am curious to see what anyone else thinks, just incase I can’t pick up a code. Especially because I haven’t had too much hands on experience. Let me know!

Measuring your fuel pressure seems like a sensible next step.

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The fuel pump would have no effect on the starter motor turning the engine over. The engine would turn over and either not start, struggle some, or even run for a while. So I would guess you got a bad battery. A failed battery may not allow a jump start. You could also have a blown computer fuse or even the fusible link. If you have a multi meter you can check the voltage on the battery. If you do get power back listen for the fuel pump to run momentarily when you turn the key to run, to rule the pump out.

Remember if the stater doesn’t run, it is electrical. Also check the battery cable connections and condition.

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Since people often use the wrong terminology ,

What do you mean by “Turn Over”?

Cranks and won’t start or Doesn’t Crank ?

The Starter Cranks/Turns Over the engine.

Then the Engine Fires/Starts


Your fuel pump would not make your starter motor not engage, If you don’t have a volt meter, order one while you are waiting for the code reader. Was your check engine light on before this happened? When your voltmeter comes, see what your battery voltage is.

Don’t assume it is not a b attery problem because a jump did not work. A dead battery can take a long time to get enough voltage to start a car from a jump.


I agree, but I wasn’t sure what the OP meant by “turn over”, as many people use that term incorrectly.


Even a $20 volt meter will be handy. Check battery voltage.

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I think so too! I will make sure to do that when the snow is cleared out. Thank you!

Gotcha, then I am probably using that term incorrectly. Everything cranks, but the car won’t start. Thank you for the heads up.

I appreciate the advice, I’ll make sure to check my battery as well when I am able to.

And no, my check engine light or any of my warning lights were on at the time. My next steps while I’m still snowed in is to listen for the fuel pump when I turn my key and do an OBD scan. Once the snow clears out, I’ll check my fuel pressure and battery.

Key on will run pump. Enough to get pressure. Your car should have a schrader valve on fuel rail. Most cars do. Depress plunger and see if fuel squirts out

Well my bad then if it cranks and no start. Yeah listen for pump. If it doesn’t run then pump likely or fuse or relay or connection. Word of caution, I have had gas squirt from the scraper valve but still not enough pressure. Need a fuel pressure tester.

Also check for spark. Spare plug, cheap spark tester. If no spark who knows but could be the crank sensor went south. I have had all these situations except a bad relay.

If no pump you can try banging on the tank. I always just towed to a shop.

If your car is cranking , you don’t have a battery problem.

Unlikely to be the cause, but one idea, if high voltage portion of ignition system gets wet, that could cause this symptom. Were you driving through rain-water puddles when you suddenly lost power?

When was the timing belt last replaced?