Loses power and shuts off while driving?

Tiny
ANNACAHILL
  • MEMBER
  • 2017 HYUNDAI ELANTRA
  • 2.0L
  • AUTOMATIC
  • 84,000 MILES
The car had a rough start and idle for a while. It's my daughter's car and she didn't tell me until after it would not start. We bought it about a year and a half ago. Right after we bought it, we had an ignition coil replaced. The car had thrown a code. Not sure of the code my husband took to dealership, and they repaired it. Seemed to address the issue. Then the car started having a rough start like it wasn't getting enough fuel but would start. I cleaned the fuel injectors and did a fuel treatment. Ran better for a few days then car shut off while driving it. Restarted right away. Then it happened again. It would crank but not start. We changed the fuel pump. Seemed to correct it but then it stopped while driving it again the next day and so far, will not restart. It's not throwing any codes. We had the battery checked. They said it holds a charge and is good. Of all the things I can find online this isn't uncommon for this car, but no one provided a solution. Please give me guidance on the issue if you are able. I'm afraid because there are no codes to take it to a dealership and not have it fixed. I think from your guides it's the crankshaft sensor.
Saturday, December 16th, 2023 AT 8:37 PM

58 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Hi,

A crankshaft position sensor would be my first guess. When they fail, you lose spark to the spark plugs. So, that is where we need to start checking.

Here is a link that explains how to check for spark, follow it and let me know the results:

https://www.2carpros.com/articles/how-to-check-for-ignition-spark

Also, if it is possible for you to record the engine cranking and upload it for me to hear, it may be helpful.

Let me know.

Joe
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Sunday, December 17th, 2023 AT 7:19 PM
Tiny
ANNACAHILL
  • MEMBER
  • 37 POSTS
Hi Joe! I have finally learned how to test and I do not have a spark. I replaced the crankshaft sensor with one that did not require relearning an Intermotor PC934. After I had installed that I got two codes for crankshaft sensor a and crankshaft sensor b. I replaced the sensors because I had purchased some anyway. I didn't really thing that would work. And it did not. I also had a mental breakdown because I dropped a nut inside the hole where the camshaft sensor was supposed to go but a trip to Walmart and a long magnet and I retrieved it. Lol. TMI? I also bought a multi meter to see if I could test the wiring to the camshaft using volts. The people in the videos doing it would get a reading of 12 and a reading of 5 for the signal wire. I got a reading of 4.8 but I did not get a reading of 12. Also, do you have a guide on how to test or does this give you any ideas? I so appreciate your help.
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Saturday, December 30th, 2023 AT 4:14 PM
Tiny
ANNACAHILL
  • MEMBER
  • 37 POSTS
Just to be more specific the codes are P0340 and P0365.
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Saturday, December 30th, 2023 AT 4:21 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Hi,

When the target triggers the cam sensor, the sensor voltage is 5V. If not, the sensor voltage is 0V. So, what you described sounds correct.

Both codes are related to the cam sensors. I have a question. Could you record the engine cranking and upload it for me to hear?

Let me know.

Joe
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Saturday, December 30th, 2023 AT 8:37 PM
Tiny
ANNACAHILL
  • MEMBER
  • 37 POSTS
Thank you for your help. Here is the requested video of cranking.
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Sunday, December 31st, 2023 AT 12:38 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Hi,

Have the camshaft position sensors been replaced? Do me a favor. At each coil, you will find a red wire. With the key in the run position, each of the red wires should have power. I need you to check that for me.

Also, I attached a few pics below. If there is no power at the coils, check the fuse in pic 1.

Let me know what you find.

Joe

See pics below.
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Sunday, December 31st, 2023 AT 5:26 PM
Tiny
ANNACAHILL
  • MEMBER
  • 37 POSTS
Yes, they have been replaced but they were generic ones from Amazon and didn't work. So, I took them off and put the OEMs back on. I did the generic ohms test on the sensor. Shows it has resistance. Do you think I should replace them?
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Sunday, December 31st, 2023 AT 5:36 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Hi,

I just updated my last post. Check for power at the coils first. I noted that the power and the engine control relay are in a printed circuit board box under the hood. In most cases, the PCB is replaced and not repaired. If we don't have power to the coils, that is what we have to check. See the prior post.

Joe
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Sunday, December 31st, 2023 AT 5:39 PM
Tiny
ANNACAHILL
  • MEMBER
  • 37 POSTS
Thank you Joe I will do this.
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Sunday, December 31st, 2023 AT 5:46 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Hi,

Sounds like a plan. Let me know what you find.

Take care and Happy New Year,

Joe
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Sunday, December 31st, 2023 AT 6:32 PM
Tiny
ANNACAHILL
  • MEMBER
  • 37 POSTS
Hey Joe,

I went outside to check for power to the coil packs last night and was not able to get the tip of the multi meter in to test. I went to harbor freight and bought a circuit tester. It had a 6/12 volt tester and a continuity tester. I used the 6/12 volt tester and showed that terminals 1 and four lit up when I probed them on each coil pack. Out of curiosity I hooked up the continuity tester. I attached it to the ground terminal of the battery and did not get the tester to light up on any of the coil packs. I am not certain I used the continuity tester the way I was supposed to though so this may not mean anything.
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Monday, January 1st, 2024 AT 9:41 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Hi,

If you connect the neg side of the tester to the battery neg terminal, you won't have continuity. I say that because the ground is provided via the PCM.

Try this. Disconnect one of the coil connectors. Locate the black wire in the connector. Check for continuity via the black wire to the battery negative and let me know what you find.

Take care,

Joe
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Monday, January 1st, 2024 AT 6:20 PM
Tiny
ANNACAHILL
  • MEMBER
  • 37 POSTS
Joe,

So, I had some time today. I used an inline spark tester last time I tested the spark plugs and recorded it with my phone. I did not see any spark. I redid the test today with a person cranking. I saw a spark at plug one and no spark on the rest of the plugs. All of the spark plugs are new. Also, the end of the spark plugs smelled like gasoline slightly. I am so sorry for all of the wrong information. Obviously, I am still learning. I also pulled out both VVT's and cleaned and tested them and put them back. Just read that it was something free that you could do that could be related to the codes I have gotten. I am now wondering if it is the bad coil packs.
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Monday, January 1st, 2024 AT 6:22 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Hi,

All of the coils wouldn't have failed at the same time, so that is unlikely. Do I understand you correctly that only cylinder 1 has spark?

As far as fuel smell, that is likely because there is no spark to burn the gas. Allow the spark plugs to be removed for a few hours so they can dry.

No need to apologize for the information. LOL We are here to help you, and that includes learning. The best way to learn is by making mistakes. (in most cases) LOL

Please confirm there is spark at the cylinder 1 coil. If there is, we need to check if power is getting to all coils. If it is, then we may have a ground issue or the PCM may have failed. I guess three coils may have failed at the same time, but that is really unlikely. If there is no spark, I need you to follow the black wires at the connectors to the rear of the cylinder head where they are mounted. Make sure that the connection is good or check the black wires for continuity to ground as I mentioned above. One other thought. I'm not sure how you are using an inline tester since these are coil packs.

Take a look at this link, you may find it helpful:

https://www.2carpros.com/articles/how-to-check-for-ignition-spark

Let me know.

Joe
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Monday, January 1st, 2024 AT 6:39 PM
Tiny
ANNACAHILL
  • MEMBER
  • 37 POSTS
Thank you so much for all of your help. I am 100% certain there is spark to the one coil, because I saw and felt it. Lol. I am going to have to charge my battery up again before I can retest the remaining plugs again but I will do that. There is voltage to the coil packs. I have checked that. I will check for continuity tomorrow. Thank you so much for the link. I will read it a few times to get a better understanding. You have been super helpful. I was on the totally wrong path on my own.
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Monday, January 1st, 2024 AT 7:46 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Anna, (I hope that's your name) LOL

You are very welcome. Let me know what you find. Once I know if the others are or aren't getting spark, I decide what to do next. Also, if cylinder one gets spark and the others don't, switch the coil from cylinder 1 to a different one not working to see if it then works. If it does, then the coils are the likely problem.

Take care,

Joe
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Monday, January 1st, 2024 AT 8:07 PM
Tiny
ANNACAHILL
  • MEMBER
  • 37 POSTS
Hey Joe!

I have retested the remaining coil packs. I have three good coil packs and one that does not get a spark. I am going to order a new coil pack but could one failing coil pack lead to a no start? I am guessing that I may have an additional issue? What's next boss? :) Also thank you for the support and encouragement.
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Tuesday, January 2nd, 2024 AT 10:39 AM
Tiny
ANNACAHILL
  • MEMBER
  • 37 POSTS
This is getting embarrassing. There is spark in all of the cylinders. So, I watched a video, sprayed starter fluid in the throttle body and it started up and obviously shut off again. I have just replaced the fuel pump, so I am at a loss.
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Tuesday, January 2nd, 2024 AT 3:42 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Hi,

When you first turn the key on, do you hear the fuel pump prime? If you do, we need to check for fuel pressure at the fuel rail. If there is pressure, then we have an injector issue. If there is no pressure, we need to recheck the fuel pump. It may not be running at all, or it could be bad.

Here is a link that explains how to check fuel pressure:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

I attached the manufacturer's fuel pressure information below. You will need a fuel pressure gauge, but most parts stores will lend one to you.

Let me know.

Joe

See pic below.
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Tuesday, January 2nd, 2024 AT 6:38 PM
Tiny
ANNACAHILL
  • MEMBER
  • 37 POSTS
Hi Joe!

I picked up a fuel pressure test kit from AutoZone to try and test the fuel pressure. I could not get the fuel feed tube separated from the delivery pipe to test it. I unscrewed the piece that went directly into the fuel rail. There was gas in the fuel rail. Also, with that opened we cranked the car and not a drop of gas came out. We do hear the fuel pump when we put the key in before we crank. I am guessing if no gas comes out, we have no fuel pressure? Any ideas on how to get the feed tube separated from the delivery pipe? I pulled and pulled but did not want to break it.
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Wednesday, January 3rd, 2024 AT 4:04 PM

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