Why does my engine have low power it will not accelerate?

Tiny
SAMCASTILLO1988
  • MEMBER
  • 2016 HYUNDAI SONATA
  • 2.4L
  • 4 CYL
  • 2WD
  • AUTOMATIC
  • 122,000 MILES
My car wont accelerate past 60 mph and very sluggish, jerky when changing gears and rpm's wont go over 2,000. I have changed spark plugs, cleaned mass airflow intake and nothing changed. Could the fuse or relay for ETC be blown, and where can I locate them on my model car?
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Sunday, June 23rd, 2019 AT 10:20 PM

49 Replies

Tiny
ASEMASTER6371
  • EXPERT
Good morning,

No, there is no blown fuse.

Is the check engine light on? If it is, do you know the code?

https://www.2carpros.com/articles/how-to-test-a-catalytic-converter

It sounds to me like your catalytic converter is clogged not allowing the engine to breathe.

https://www.2carpros.com/articles/engine-has-low-power-output

Roy

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Monday, June 24th, 2019 AT 3:30 AM
Tiny
DANMART89
  • MEMBER
  • 2013 HYUNDAI SONATA
  • 2.4L
  • 2WD
  • AUTOMATIC
  • 180,000 MILES
Car sometimes does not want to accelerate. I have to let go of gas while driving in order to catch again.
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Friday, March 19th, 2021 AT 9:43 AM (Merged)
Tiny
JACOBANDNICKOLAS
  • EXPERT
Welcome to 2CarPros.

Have you checked fuel pump pressure? What you described sounds like it is starved for fuel. It could be as simple as a partially plugged fuel filter or a weak pump. What I recommend first is to check fuel pressure to confirm it is within the manufacturer's specs.

Here is a link that explains in general how it is done:

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

Here are the directions specific to your vehicle. They include the manufacturer's specs for pressure. However, they also include info related to a bleed down test which isn't the issue. The attached pics correlate with the directions.

____________________

2013 Hyundai Sonata L4-2.4L
Component Tests and General Diagnostics
Vehicle Powertrain Management Fuel Delivery and Air Induction Fuel Pump Fuel Pressure Testing and Inspection Component Tests and General Diagnostics
COMPONENT TESTS AND GENERAL DIAGNOSTICS
Fuel Pressure Test

1. Release the residual pressure in fuel line .

CAUTION:
When removing the fuel pump relay, a Diagnostic Trouble Code (DTC) may occur. Delete the code with the GDS after completion of "Release Residual Pressure in Fuel Line" work.

2. Install the Special Service Tool (SST).
(1)Disconnect the fuel feed tube from the high pressure fuel pump.

CAUTION:
There may be some residual pressure even after "Release Residual Pressure in Fuel Line" work, so cover the hose connection with a shop towel to prevent residual fuel from spilling out before disconnecting any fuel connection.

(2)Install the special service tool for measuring the fuel pressure in between the fuel feed tube and the high pressure fuel pump .

pic 1

3. Inspect fuel leakage on connections among the fuel feed tube, the high pressure fuel pump, and the SST components with IG ON.
4. Measure Fuel Pressure.
(1)Start the engine and measure the fuel pressure at idle.

Fuel Pressure:445 - 455 kPa (4.5 - 4.6 kgf/cm2, 64.5 - 66.0 psi)

NOTE:
If the fuel pressure differs from the standard value, repair or replace the related part .

pic 2

(2)Stop the engine, and then check for the change in the fuel pressure gauge reading.

Standard Value:The gauge reading should hold for about 5 minutes after the engine stops

NOTE:
If the gauge reading should not be held, repair or replace the related part .

pic 3

(3)Turn the ignition switch OFF.
5. Release the residual pressure in fuel line .

CAUTION:
When removing the fuel pump relay, a Diagnostic Trouble Code (DTC) may occur. Delete the code with the GDS after completion of "Release Residual Pressure in Fuel Line" work.

6. Test End
(1)Remove the Special Service Tool (SST) from the fuel feed tube and the high pressure fuel pump.
(2)Connect the fuel feed tube and the high pressure fuel pump.

Fuel Pressure Test

1. Release the residual pressure in fuel line .

CAUTION:
When removing the fuel pump relay, a Diagnostic Trouble Code (DTC) may occur. Delete the code with the GDS after completion of "Release Residual Pressure in Fuel Line" work.

2. Install the Special Service Tool (SST).
(1)Disconnect the fuel feed tube from the high pressure fuel pump.

CAUTION:
There may be some residual pressure even after "Release Residual Pressure in Fuel Line" work, so cover the hose connection with a shop towel to prevent residual fuel from spilling out before disconnecting any fuel connection.

(2)Install the special service tool for measuring the fuel pressure in between the fuel feed tube and the high pressure fuel pump .

pic 4

3. Inspect fuel leakage on connections among the fuel feed tube, the high pressure fuel pump, and the SST components with IG ON.
4. Measure Fuel Pressure.
(1)Start the engine and measure the fuel pressure at idle.

Fuel Pressure:480 - 520 kPa (4.9 - 5.3 kgf/cm2, 69.6 - 75.4 psi)

NOTE:
If the fuel pressure differs from the standard value, repair or replace the related part .

pic 5

(2)Stop the engine, and then check for the change in the fuel pressure gauge reading.

Standard Value:The gauge reading should hold for about 5 minutes after the engine stops

NOTE:
If the gauge reading should not be held, repair or replace the related part .

pic 6

(3)Turn the ignition switch OFF.
5. Release the residual pressure in fuel line .

CAUTION:
When removing the fuel pump relay, a Diagnostic Trouble Code (DTC) may occur. Delete the code with the GDS after completion of "Release Residual Pressure in Fuel Line" work.

6. Test End
(1)Remove the Special Service Tool (SST) from the fuel feed tube and the high pressure fuel pump.
(2)Connect the fuel feed tube and the high pressure fuel pump.

_________________________________

If you find the fuel filter or the pump is the issue, here are the directions for replacement. Note that to replace the filter, you have to remove the fuel pump from the tank. Note, if you have to replace the fuel pump, make sure to do the filter at the same time.

2013 Hyundai Sonata L4-2.4L
Removal and Replacement
Vehicle Powertrain Management Fuel Delivery and Air Induction Fuel Filter Service and Repair Removal and Replacement
REMOVAL AND REPLACEMENT
Replacement

1. Remove the fuel pump .
2. Disconnect the electric pump wiring connector (A) and the fuel sender connector (B), and then remove the fuel sender (C).
3. Disconnect the fuel tube quick-connector (D).
4. Remove the head assembly (E) after releasing the fixing hooks.

pic 7

5. Disconnect the fuel feed tube quick-connector (A).
6. Remove the fixing clip (B), and then disconnect the fuel tube (C).
7. Remove the reservoir-cup (D) after releasing the fixing hooks.

pic 8

8. Disconnect the ground cable (A).
9. Remove the cap (B), and then remove the assist pump (C) and the fuel pressure regulator (D).

pic 9

CAUTION:
Be careful of O-ring.

10. Separate the electric pump motor from the fuel filter after releasing the fixing hooks (A).

pic 10

pic 11

pic 12

1. Head Assembly
2. Electric Pump Motor
3. Fuel Filter
4. Fuel Sender
5. Fuel Pressure Regulator
6. Assist Pump
__________________________________________

Here are the directions for removal and replacement of the pump assembly.

2013 Hyundai Sonata L4-2.4L
Fuel Pump
Vehicle Powertrain Management Fuel Delivery and Air Induction Fuel Pump Service and Repair Removal and Replacement Fuel Pump
FUEL PUMP
Removal

1. Release the residual pressure in fuel line .
2. Remove the fuel pump service cover (A) in the trunk.

pic 13

3. Disconnect the fuel pump connector (A) and the fuel tank pressure sensor connector (B).
4. Disconnect the fuel feed tube quick connector (C) and the vapor tube quick-connector (D).
5. Remove locking ring (E) by use the special service tool [SST No. : 09310-2S200].

pic 14

6. Disconnector the vapor tube quick-connector (A) at the fuel pump, and then remove the fuel pump from the fuel tank.

pic 15

pic 16

Installation

1. Installation is reverse of removal.

CAUTION:
Be careful of fuel pump direction.

_________________________________________

Let me know if this helps or if you have other questions.

Take care,
Joe
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Friday, March 19th, 2021 AT 9:43 AM (Merged)
Tiny
PBFENERGY
  • MEMBER
  • 2012 HYUNDAI SONATA
  • 2.4L
  • 4 CYL
  • 2WD
  • AUTOMATIC
  • 140,000 MILES
Car will not accelerate past forty mph and rpm's will go up and car will not shift at forty mph. Malfunction light is also lit.
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Friday, March 19th, 2021 AT 9:43 AM (Merged)
Tiny
MHPAUTOS
  • EXPERT
It sounds like you have a weak fuel pump, clogged catalytic converter or a bad MAF or MAP sensor but to be sure we should run the codes by checking out this guide.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

we should also go over this guide as well.

https://www.2carpros.com/articles/engine-has-low-power-output

Please run down these guides and report back.
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Friday, March 19th, 2021 AT 9:43 AM (Merged)
Tiny
RENEE L
  • ADMIN
Hello PBFENERGY,

I am sending you a link to an article that features written step by step instructions and pictures explaining how to scan for codes yourself. Also, I have included a link to our YouTube channel with a how to video on code scanning.

This is applicable even if your check engine light is not on.

Most scanners are inexpensive to purchase, you can purchase one online from sites like Amazon.com

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

https://youtu.be/YV3TRZwer8k

Once you have the codes please get back to us so that we can further assist you. We are always happy to help.

Thank you for visiting 2CarPros.com.

Kindest regards,
Renee

Admin
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Friday, March 19th, 2021 AT 9:43 AM (Merged)
Tiny
GAO7857
  • MEMBER
  • 2008 HYUNDAI SONATA
  • 4 CYL
  • 2WD
  • AUTOMATIC
  • 150,000 MILES
Car listed above is the GLS model.I Changed full synthetic engine oil, filter and air filter 12/17, rotated tires. Drove a bit locally without issue. On 12/20, it was raining, the car did not accelerate properly when entering highway. After about 20-30 miles/hr, pressing down the pedal won’t accelerate further. When press pedal all the way to the bottom, still not acceleration and the engine speed is just 2000 to 3000 rpm. When depress the pedal can feel the car choke a bit. On the way back via local, couple times it did accelerate to about 40-50 miles/hour, if I slowly and gently press the pedal. The temperature looks normal. Engine light is off, so are other lights. The car just passed its 150,000 miles mark. Any suggestions what could go wrong? Transmission? Brake pedal stopper?  Others?
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Friday, March 19th, 2021 AT 9:44 AM (Merged)
Tiny
JACOBANDNICKOLAS
  • EXPERT
Hi,

Interestingly, when you press on the throttle, you seem to have less power. Often times that is caused by a weak fuel pump. When you press the throttle, the engine requires more fuel.
If it isn't available, what you described can happen. Since it was running okay after the oil change, that is the first thing I would check. Here is a link that explains how to check pressure:

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

Here are the manufacturer's specs for pressure:

Standard Value: .................... 345 - 355 kpa(3.51 - 3.61 kg/sq.cm, 50.0 - 51.5 psi)

_________________________

My next question is this. I have seen situations where the catalytic converter has come apart internally and the guts move around, usually making a rattling sound. What can happen in this case is when the engine begins to rev, the guts restrict air flow and the vehicle experiences power loss. If you question this, take a rubber mallet and tap on the exhaust to see if there is any noise coming from the converter. Also, here is a test for checking for converter issues:

https://www.2carpros.com/articles/how-to-test-a-catalytic-converter

Here is a link explaining common symptoms of a catalytic converter issue. See if anything seems to mirror what you experience.

https://www.2carpros.com/articles/bad-catalytic-converter-symptoms

Let me know what you find. Also, let me know if you have other questions.

Take care,
Joe
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Friday, March 19th, 2021 AT 9:44 AM (Merged)
Tiny
GAO7857
  • MEMBER
Hi JACOBANDNICKOLAS,

Thank you for your time and suggestions. I checked couple things last night and the car somehow become running normal again. I will describe the details so not miss anything. Even though it seems runs again I still like to figure out what was wrong and fix it, so it does not come back again.

I checked the code although no engine light. No code. When I turn the key to on position the hissing sound was like before, indicating the fuel pump works at least, and maybe normally.

Turned the key to start, and found that the battery was low, so the engine is cranking but wont start, even when I pedal on for about 10 seconds. This reminds me (I forgot to mention) that on 12/20 when it did not accelerate properly, the battery was also low at start, but the engine was able to start when pedal on for a few seconds, and I drove out without waiting for the battery to be charged. I used the jump starter and the car started right away. When the car starts from cold it always has some cyclic grinding sound for a few minutes around crankshaft and camshaft, that I was believing to be due to the interference at cold temperature. This time I opened the hood and try to see if there is anything abnormal in that region. The car was running for about couple minutes and the grinding sound diminished as in the past.

I then stopped the engine. The battery red pole has no build up. I checked the air filter counter part. No debris from the air filter to the engine as I can tell, although I can not see the air entrance to the engine. The pipe seems clean. I removed the air mass flow sensor, and it looks clean too.

I need to get a fuel pressure gauge to measure the fuel pressure, and plan to check the catalytic converter the same time when I jack up the car. So last night I turns on the engine again without the jumper, and it started right away. I drove it out and everything becomes normal†I tried accelerate to 60 miles/hr and there is no hesitation of acceleration.

So the battery is my culprit and here is my theory. On 12/20 I marginally started the car with a low battery and immediately went on the road. The battery was still low, while I turned on the head light, the AC heater & defrost to high power, and also the stereo. The battery was barely charged when the car hit high way. So when I pedal up to enter high way, the battery cannot provide the power to the fuel pump to get more gas to the engine. Today when I went to O'Reilly I will also ask the battery be checked out, and probably get a replacement battery if confirmed. I will update when back from the store.

What do you think?
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Friday, March 19th, 2021 AT 9:44 AM (Merged)
Tiny
GAO7857
  • MEMBER
The battery is bad. The alternator is good. Replaced the battery and it drives good. I will drive and see for a few days. Thank you for the help so far.
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Friday, March 19th, 2021 AT 9:44 AM (Merged)
Tiny
JACOBANDNICKOLAS
  • EXPERT
At this point, I suspect you are correct. A weak battery on today's cars can play havoc with the electronics. See if it continues to run normally. However, I do have a question. Do you mean you have to press the accelerator to start the engine? If that is the case, you may have a bad fuel pressure regulator. That would be checked when checking fuel pressure. It may just be too high and feeding too much fuel to the engine. When you press the throttle pedal to the floor, it basically shuts down the injection to prevent flooding.

Let me know.

Joe
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Friday, March 19th, 2021 AT 9:44 AM (Merged)
Tiny
BENASMITH
  • MEMBER
  • 2006 HYUNDAI SONATA
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 76,500 MILES
My son's car will sometimes lose power while driving. It doesn't die, but it won't accelerate. He pulls to the side of the road, turns it off and then back on again and it works fine. When it happens the check engine light comes on and after he turns it off and back on again, the check engine light goes off.
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Friday, March 19th, 2021 AT 9:45 AM (Merged)
Tiny
JPMJPM20
  • MEMBER
I have a 2006 Sonata limited V6. I have experienced a similar problem. It happens intermittently. When I am passing, I accelerate the engine revs (as if it is in neutral) and there is no acceleration and in most cases the check engine light comes on. This has been happening several times between 30,000 and 71,000 miles. I have taken it to the dealer each time. They replace a MAP sensor, wire harness, or other component and claim it has been fixed.
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Friday, March 19th, 2021 AT 9:45 AM (Merged)
Tiny
JAGUAR1957
  • MEMBER
  • 2006 HYUNDAI SONATA
  • 6 CYL
  • FWD
  • AUTOMATIC
  • 80,000 MILES
HI I have taken code from computer they are as follows: 2106, 1295, 2135. I need the problems for these codes and any information.
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Friday, March 19th, 2021 AT 9:45 AM (Merged)
Tiny
DOCFIXIT
  • EXPERT
Hi
All codes are for faults in Electronic Throttle Control to determine if replacement is needed a diagnostic scan of codes will be needed. Location see diagram


https://www.2carpros.com/forum/automotive_pictures/198357_Graphic_551.jpg


Hope this helps
Thanks for donate
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Friday, March 19th, 2021 AT 9:45 AM (Merged)
Tiny
ANOTHERBADDCREATION
  • MEMBER
  • 2004 HYUNDAI SONATA
  • 112,000 MILES
The check engine light came on then a knock then a loss of power, When I stopped the car the engine was knocking and shaking violently. Is this a timing belt tensioner.
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Friday, March 19th, 2021 AT 9:46 AM (Merged)
Tiny
HMAC300
  • EXPERT
If it's aknock I dont' think so. Have apro listen to this as it's very hard to diagnose, but sounds like something major
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Friday, March 19th, 2021 AT 9:46 AM (Merged)
Tiny
ANOTHERBADDCREATION
  • MEMBER
I dont like magor saw somewhere it could be an egr so am hoping it is not to bad
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Friday, March 19th, 2021 AT 9:46 AM (Merged)
Tiny
HMAC300
  • EXPERT
We really can't hear it so we have to suspect major with aloss of power. If it is aheavy knowck then it wouldn't be an egr valve
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Friday, March 19th, 2021 AT 9:46 AM (Merged)
Tiny
ANOTHERBADDCREATION
  • MEMBER
It is heavy heavy might have the timming chain done to cant get it on a code reader had to tow it home did not want to tear it up worse. Thank you and I will let you know what they find out
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Friday, March 19th, 2021 AT 9:46 AM (Merged)

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