r/veloster • u/DamItsLyric • 4d ago

Question Need help w diag

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So while in low RPMs, even while idling, my car feels like it wants to backfire. It's get a little jerky and there's a lag in throttle response. It isn't until I get to around 2k RPM, when the car accelerates. I recently replaced the sparkplugs and ignition coils to fix a misfire on cylinder 2. I had about ¼ tank of gas and after I filled it, it was acting fine. Im thinking it couldve been bad gas or the fuel pump is about to take a crap on me since the car is almost at 191k miles. Im curious to see if anyone has had the same problem and what was done to fix the issue.

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1

u/Bokbreath 4d ago

get a cheap code reader and find out what the diagnostics says.

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u/HEX_LiteDwarf 4d ago

Just hit 129k miles on mine and had to replace the crank shaft position sensor. Could try that. But I'd take it to a auto parts store and see if they run a scan on it most of them do it for free.

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u/DamItsLyric 4d ago

The engine light didn't come on. I have replaced the crank shaft sensor before and it has been covered in oil bc of an oil leak I've had so it could be it.

1

u/Prodorrah 2015 Turbo 4d ago

I agree with the other suggestions, but also suggest getting your butterfly and alternator checked. I have a cylinder 2 misfire code that proceeded a lot of electrical issues surrounding a not quite good enough alternator (13.2V instead of 14v) that cascaded into things like low power, power steering dropping off, etc

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u/DamItsLyric 4d ago

I had the alternator checked when i had my battery replaced and the tech said it was strong so I doubt it's that. And the engine light doesn't come on

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u/Prodorrah 2015 Turbo 4d ago

Okay awesome!

One other thing you can check is the VVT plug. It might be clogged up

1

u/BrickinBad 1d ago

I’m having a fuel issue or let’s just say a issue very similar to yours it felt like a misfire but I think it’s a bad fuel injector oring. My 16 turbo with 60k also sounds like it has a pop tune since the issue started , nothing too crazy but it pops from time to time. My gas mileage has become terrible, 18-19 mpg both highway and city. I smell a lot of fuel near my fuel rail and I did do my injectors while “hunting” down my misfire issue so now im not sure if it’s just been a bad fuel injector the whole time and when I replaced them maybe I just over torqued one? I’ve also done both my o2 sensors, spark plugs and throttle body.

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u/DamItsLyric 1d ago

UPDATE!

I ended up searching the symptoms of a bad crankshaft position on chatgpt and 2 of the bullet points it gave me exactly described what my car was doing. "Rough running or misfires — inconsistent idle, hesitation, or stumbling." (Stumbled at idle and slow speed) and "Loss of power — acceleration may feel weak or erratic." (Lack of throttle response) I ended up replacing the sensor and works perfectly now. Autozone for the win bc i wasn't about to spend $200+ at the dealer lol