Cylinder misfire, car won't start

I have a 2011 Kia Soul that stopped running. It was running when I parked it in the driveway on Friday, but then refused to start on Saturday morning. It cranks, but won’t start. Checking for OBD-II codes, I saw a P0303 (misfire in cylinder 3). I have never troubleshooted a misfire before, so I started looking online for possible causes and potential solutions. Everything I’m finding online suggests that a misfire in a single cylinder (or even two cylinders) doesn’t usually prevent a car from starting. But then again, maybe that’s different in a 4-cylinder, I don’t know. Also, when I try to start it, the engine shakes rather violently as it cranks.

Would it be best to start with the basics, like checking coils and plugs? Or is the fact that a single cylinder misfire is preventing the engine from starting a sign that something else is wrong? I cleared the codes and tried to start it again, and got the same P0303. No misfires in any other cylinders were reported.

Thanks for taking the time to read!! :slight_smile:

A bad crankshaft position sensor can cause cylinder misfires and prevent the engine from starting.

https://www.1aauto.com/content/articles/bad-crankshaft-position-sensor-symptoms

Tester

Okay, thanks! I will test that sensor with a multimeter, as that page suggests.

I assume so, since you mentioned it, but would it make sense that that sensor would cause misfires in one cylinder consistently, or would it more likely be distributed across multiple cylinders?

Hey! Thanks for your help yesterday. I can’t find the crank sensor on the car… but I read on this other page that “the computer won’t provide the engine with spark without a crankshaft position sensor signal. This will result in an engine that cranks but doesn’t start.” (https://repairpal.com/crankshaft-position-sensor)

We tested for a spark yesterday, and cylinder 3 seems to be sparking just fine. We also tested cylinder 1, just for giggles, and its performance was identical to cylinder 3. I’m also not receiving DTC P0335, which would indicate a failed sensor.

Is it still possible the crank sensor if wearING out, as opposed to worn out, or is the most likely cause fuel related instead, do you think?

Thank you! :slight_smile:

One thing never goes out of style- the divide and conquer approach. You have spark. Do you have fuel? The easiest way to find out if it’s fuel related is to spritz some starting fluid into the intake and try cranking it over. It if spits and sputters and runs briefly, you know you have a fuel supply problem and can start looking there…then check for fuel rail pressure etc

That makes sense! Thank you. I will pick up a can of starting fluid and try this sometime this morning!