# 2019 Hyundai Veloster Misfires **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** hyundai, engines\ **Created:** [June 6, 2025, 3:24pm UTC](https://community.cartalk.com/t/2019-hyundai-veloster-misfires/200545 "2025-06-06T15:24:49Z")\ **Posts on this page:** 18\ **Page:** 1
**Author:** ![Dakotawoodsusa\_192743](https://avatars.discourse-cdn.com/v4/letter/d/9d8465/32.png) [@Dakotawoodsusa\_192743](https://community.cartalk.com/u/Dakotawoodsusa_192743)\ **Post date:** [June 6, 2025, 3:24pm UTC](https://community.cartalk.com/t/2019-hyundai-veloster-misfires/200545/1 "2025-06-06T15:24:49Z")
**2019 Hyundai Veloster Turbo 1.6L GDI – Cold Start Misfire & Rough Idle Issue** I’m troubleshooting a misfire issue in my Veloster Turbo that occurs **only on cold starts**. It misfires on **cylinders 1 and 2** , and I get rough idling **only in the morning** upon the first start. Once it warms up, the engine smooths out and runs fine. ### **Symptoms:** - **Cold Start Rough Idle** – Runs rough only during the first startup of the day. - **Cylinder 1 & 2 Misfire Codes** – Initially, only cylinder 2 had a misfire, but now cylinder 1 does as well. - **Jittering When Creeping Forward** – In the morning, when I **release the brake without pressing the gas** (such as backing out of a driveway or rolling forward), the car **jerks badly**. - **Intermittent Jittering at Low Speed** – Occasionally, when slowly rolling forward (like in a drive-thru), I get similar jittering. ### **Repairs Done So Far:** - **New Spark Plugs** – Replaced all plugs. - **New Coil Pack for Cylinder 2** – Misfire persisted, and now cylinder 1 is also affected. I put Techron Fuel cleaner hoping maybe an injector could be clogged from carbon? Its got 122,000k. But whats weird is after the morning roughness idle the car shifts fine. Not stuttering no fluctuations in rpms. The engine idles very smoothly. And gets up and goes pretty well. ---
**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\ **Post date:** [June 6, 2025, 3:27pm UTC](https://community.cartalk.com/t/2019-hyundai-veloster-misfires/200545/2 "2025-06-06T15:27:20Z")
I’d have the intake system inspected for carbon buildup, a common problem on these GDI engines. If it’s the problem Techron won’t help, may not have helped prevent it, either. Only a thorough cleanout will work. ---
**Author:** ![asemaster](https://avatars.discourse-cdn.com/v4/letter/a/5f9b8f/32.png) [@asemaster](https://community.cartalk.com/u/asemaster)\ **Post date:** [June 6, 2025, 3:28pm UTC](https://community.cartalk.com/t/2019-hyundai-veloster-misfires/200545/3 "2025-06-06T15:28:37Z")
How many fuel injection/intake services has the car had in 122,000 miles? If it were mine it would have had the intake and injection service done 4 times by now. How does the engine run under load, as in merging on to the freeway with the pedal to the floor? ---
**Author:** ![Dakotawoodsusa\_192743](https://avatars.discourse-cdn.com/v4/letter/d/9d8465/32.png) [@Dakotawoodsusa\_192743](https://community.cartalk.com/u/Dakotawoodsusa_192743)\ **Post date:** [June 6, 2025, 3:29pm UTC](https://community.cartalk.com/t/2019-hyundai-veloster-misfires/200545/4 "2025-06-06T15:29:31Z")
Okay. Maybe have it walnut blasted? Is it possible i could have a leaking injector where it sets over night? I thought about the valves but wouldnt i be seeing that roighbidle no go away? But only upon startup? I wanted to ask is it possible an injector could be leaking over night after it sits to much fuel is on the cylinder head? Then when i start it up its got to burn that fuel off? ---
**Author:** ![Dakotawoodsusa\_192743](https://avatars.discourse-cdn.com/v4/letter/d/9d8465/32.png) [@Dakotawoodsusa\_192743](https://community.cartalk.com/u/Dakotawoodsusa_192743)\ **Post date:** [June 6, 2025, 3:33pm UTC](https://community.cartalk.com/t/2019-hyundai-veloster-misfires/200545/5 "2025-06-06T15:33:50Z")
No its response to throttle is great. It runs and idles fine has no problem. Its just only in the morning with that first quirk. I can reset the code it will go away and stay off. But will return after that next morning start up. The valves have not be done yet. I run techron in the fuel every 3,000 miles. ---
**Author:** ![Mustangman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mustangman/32/44130_2.png) [@Mustangman](https://community.cartalk.com/u/Mustangman)\ **Post date:** [June 6, 2025, 3:39pm UTC](https://community.cartalk.com/t/2019-hyundai-veloster-misfires/200545/6 "2025-06-06T15:39:30Z")
> [@Dakotawoodsusa\_192743](#): > > I run techron in the fuel every 3,000 miles You engine is direct injection so the Techron might keep your injectors clean but it does nothing for carbon buildup on the backsides of the intake valves. Direct injection fuel injectors spray fuel directly into the combustion chamber… it never sprays on the backsides of the valves to keep them clean. There are chemical treatments that are introduced into the intake manifold that help keep the valves clean. Buildup can cause problems like you are having. A boroscope into the intake manifold can show you if the valves need physical mechanical cleaning… solvent and scrape or walnut blasting. I’d try a chemical cleaner first… something like this; > **[Amazon.com: Berryman Products 2611 Intake Valve and Combustion Chamber Cleaner,...](https://www.amazon.com/Berryman-Combustion-Chamber-Cleaner-16-Ounce/dp/B081TKBG18)** > > After 100 years in business, we are especially grateful to our customers who make us what we are today. We commit to continue providing products that meet the highest quality standards of performance, reliability and environmental responsibility. ---
**Author:** ![Dakotawoodsusa\_192743](https://avatars.discourse-cdn.com/v4/letter/d/9d8465/32.png) [@Dakotawoodsusa\_192743](https://community.cartalk.com/u/Dakotawoodsusa_192743)\ **Post date:** [June 6, 2025, 3:45pm UTC](https://community.cartalk.com/t/2019-hyundai-veloster-misfires/200545/7 "2025-06-06T15:45:23Z")
I bought some GDI cleaner removed the throttle body and had my friend rev it while i sprayed it in. It seemed to have helped my turbo a bit. But the codes never retreated nor the rough idle in the morning. This light is driving me nuts..and the bad jittering because its running fine after that. I can set a drink on the engine and it barely vibrates. I was trying to edit my post i accidentally deleted. But is it possible an Injector could be leaking over night? And then to much fuel is on the cylinder head and its causing that morning craziness. Although i need to get the valves done, wouldnt i be seeing that rough idle through out the day? If a valve wasnt able to open up fully like its supposed too? ---
**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\ **Post date:** [June 6, 2025, 3:47pm UTC](https://community.cartalk.com/t/2019-hyundai-veloster-misfires/200545/8 "2025-06-06T15:47:28Z")
The deposits could be thick enough that no spray will make a dent in them. Only a visual inspection up to the intake valves will give you the answer. ---
**Author:** ![Mustangman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mustangman/32/44130_2.png) [@Mustangman](https://community.cartalk.com/u/Mustangman)\ **Post date:** [June 6, 2025, 3:50pm UTC](https://community.cartalk.com/t/2019-hyundai-veloster-misfires/200545/9 "2025-06-06T15:50:14Z")
> [@Dakotawoodsusa\_192743](#): > > is it possible an Injector could be leaking over night That would give you a long crank time in the morning at first start. > [@Dakotawoodsusa\_192743](#): > > And then to much fuel is on the cylinder head and its causing that morning craziness No, too little fuel but only initially.. seconds. > [@Dakotawoodsusa\_192743](#): > > Although i need to get the valves done, wouldnt i be seeing that rough idle through out the day Not necessarily… Cold start is a different condition than a warm idle. > [@Dakotawoodsusa\_192743](#): > > If a valve wasnt able to open up fully like its supposed too? That isn’t what happens. The valve opens fully because the cam opens it. The issue is obstructed airflow past the valves. You need to have a look inside. Either scope it or remove the intake manifold and look. ---
**Author:** ![Dakotawoodsusa\_192743](https://avatars.discourse-cdn.com/v4/letter/d/9d8465/32.png) [@Dakotawoodsusa\_192743](https://community.cartalk.com/u/Dakotawoodsusa_192743)\ **Post date:** [June 6, 2025, 3:51pm UTC](https://community.cartalk.com/t/2019-hyundai-veloster-misfires/200545/10 "2025-06-06T15:51:33Z")
Okay. Yeah i will definitely leave that up to a specialist. And have them checked at the least walnut blasted if its bad. ---
**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\ **Post date:** [June 6, 2025, 3:51pm UTC](https://community.cartalk.com/t/2019-hyundai-veloster-misfires/200545/11 "2025-06-06T15:51:48Z")
Here’s the scope @Mustangman is referring to (example, pro’s version much better): ![image](https://global.discourse-cdn.com/cartalk/original/3X/0/7/07526e3035f004eea2c0fcf8864344ee61e6d8d8.jpeg) ---
**Author:** ![davesmopar](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/davesmopar/32/41750_2.png) [@davesmopar](https://community.cartalk.com/u/davesmopar)\ **Post date:** [June 6, 2025, 4:20pm UTC](https://community.cartalk.com/t/2019-hyundai-veloster-misfires/200545/12 "2025-06-06T16:20:38Z")
I’m just gonna ask, you only have 2 codes right, a P0301 and a P0302??? No others?.. Anything look odd in Live Data?? ---
**Author:** ![Dakotawoodsusa\_192743](https://avatars.discourse-cdn.com/v4/letter/d/9d8465/32.png) [@Dakotawoodsusa\_192743](https://community.cartalk.com/u/Dakotawoodsusa_192743)\ **Post date:** [June 6, 2025, 4:38pm UTC](https://community.cartalk.com/t/2019-hyundai-veloster-misfires/200545/13 "2025-06-06T16:38:27Z")
Yes Only those 2 codes. P0300. “Multiple misfire within a time period” can you guys tell me what the average price of having a walnut blasting would be? Also thank you guys for being so quick to help! ---
**Author:** ![VOLVO-V70](https://avatars.discourse-cdn.com/v4/letter/v/8e8cbc/32.png) [@VOLVO-V70](https://community.cartalk.com/u/VOLVO-V70)\ **Post date:** [June 6, 2025, 4:58pm UTC](https://community.cartalk.com/t/2019-hyundai-veloster-misfires/200545/14 "2025-06-06T16:58:33Z")
> [@Dakotawoodsusa\_192743](#): > > can you guys tell me what the average price Since prices vary by location any guess we make might not even be close . Google says 300.00 to 1000.00 ---
**Author:** ![Dakotawoodsusa\_192743](https://avatars.discourse-cdn.com/v4/letter/d/9d8465/32.png) [@Dakotawoodsusa\_192743](https://community.cartalk.com/u/Dakotawoodsusa_192743)\ **Post date:** [June 6, 2025, 5:17pm UTC](https://community.cartalk.com/t/2019-hyundai-veloster-misfires/200545/15 "2025-06-06T17:17:32Z")
So i called around and only found 1 shop in North Carolina that can do it. They wanna scope it first to make sure thats what it is. He said it is pricey. They haven’t done it alot. But they have done it before…i also called another shop and the guy said it sounds like water is getting into the cylinder? Is this possible?.. ---
**Author:** ![db4690](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/db4690/32/2583_2.png) [@db4690](https://community.cartalk.com/u/db4690)\ **Post date:** [June 6, 2025, 5:19pm UTC](https://community.cartalk.com/t/2019-hyundai-veloster-misfires/200545/16 "2025-06-06T17:19:42Z")
I strongly suspect if you were to look at live data and mode 6 data, you’d discover misfires on ALL cylinders Don’t assume #3 and #4 are “fine” ---
**Author:** ![Dakotawoodsusa\_192743](https://avatars.discourse-cdn.com/v4/letter/d/9d8465/32.png) [@Dakotawoodsusa\_192743](https://community.cartalk.com/u/Dakotawoodsusa_192743)\ **Post date:** [June 6, 2025, 5:23pm UTC](https://community.cartalk.com/t/2019-hyundai-veloster-misfires/200545/17 "2025-06-06T17:23:19Z")
Im not a professional. But i didnt read the codes i had a shop run them. Then connect it to pc. And it said cylinder 1 and 2. ---
**Author:** ![Nevada\_545](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/nevada_545/32/41232_2.png) [@Nevada\_545](https://community.cartalk.com/u/Nevada_545)\ **Post date:** [June 6, 2025, 6:23pm UTC](https://community.cartalk.com/t/2019-hyundai-veloster-misfires/200545/18 "2025-06-06T18:23:55Z")
> [@Dakotawoodsusa\_192743](#): > > But is it possible an Injector could be leaking over night? And then to much fuel is on the cylinder head and its causing that morning craziness. Yes. I have replaced a few high-pressure fuel injectors because of leaking after shut-down. Inspect the spark plugs, the cylinder with the leaking injector will usually be black with carbon deposits on the center electrode insulator. You can inspect the cylinders while warm with a borescope for the presence of fuel or coolant.