Car is driving not accelerating?

Tiny
ECLIPSEKRYPT
  • MEMBER
  • 1999 MITSUBISHI ECLIPSE
  • 2.0L
  • 4 CYL
  • 2WD
  • AUTOMATIC
  • 80,000 MILES
When I drive it seems like it does not want to accelerate. I push the gas and it is slow to get up in speed. I feel some vibration in the steering wheel, but RPM is normal. I changed spark plugs, wires, camshaft sensor, cleaned throttle body, changed air filter and some vacuum hoses. Mounts seem good. What can be going on? Thanks in advance.
Wednesday, September 7th, 2022 AT 5:35 PM

11 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Hi,

This could be the result of a few things. Anytime there is a power loss, I always check to make sure the catalytic converter isn't partially plugged. Take a look through this link and let me know if anything seems to mirror what you experience:

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

Next, have you checked fuel pressure to see if it is within the manufacturer's specifications?

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

If you look at the attached pic below, it includes the manufacturer's fuel pressure specifications.

Try these two things. Also, let me know if the check engine light is staying on while the engine is running.

Take care,

Joe

See pic below.
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Wednesday, September 7th, 2022 AT 8:24 PM
Tiny
ECLIPSEKRYPT
  • MEMBER
  • 17 POSTS
I forgot to mention this car has headers and an exhaust system. The catalytic was taken out. I will check the fuel pressure to see if that might be the case. Anything else you recommend me to check. Thank you
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Thursday, September 8th, 2022 AT 9:08 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Hi,

This isn't an issue that started just since the header was installed, correct? As far as the description, I would start with the fuel pressure. If that isn't the cause, we will go from there.

Take care,

Joe
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Thursday, September 8th, 2022 AT 6:35 PM
Tiny
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  • MEMBER
  • 17 POSTS
No, I installed the headers years ago. The car worked perfectly. It has been about a month or so since the changes, which is why I did the tune up. Thanks for your response.
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Friday, September 9th, 2022 AT 12:48 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Hi,

Okay. I was thinking that could be the issue. However, the first thing I suggest is to check fuel pressure. If you have questions or if I can help in any way, let me know.

Take care,

Joe
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Friday, September 9th, 2022 AT 8:38 PM
Tiny
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  • MEMBER
  • 17 POSTS
Thank you. I am checking it as I am typing this, I will keep you posted.
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Saturday, September 10th, 2022 AT 7:25 AM
Tiny
ECLIPSEKRYPT
  • MEMBER
  • 17 POSTS
The mechanic told me it was at 50. He said it had perfect pressure. Recommended me to put an octane additive. I did and drove it for a while. Didn't really see any change.
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Saturday, September 10th, 2022 AT 10:03 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Hi,

That is on the high end of pressure when the regulator is disconnected. So, yes, it should be fine. By chance, did he write down on the receipt if that was the pressure with the regulator vacuum disconnected? Just to confirm. With the regulator connected it should be approximately 38 PSI at idle.

If that is good, it's tuned up, the check engine light doesn't stay on, and you already did all the things you mentioned in the first post, I have to ask. Is the timing belt original? It shouldn't be bad at 80,000, but it does have several years on it.

Let me know.

Joe
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Saturday, September 10th, 2022 AT 7:25 PM
Tiny
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  • MEMBER
  • 17 POSTS
I had it changed about 2 years back. So, I would say it has about 10,000 miles on it. I noticed the check engine light was on and after driving awhile it turns off. Then after a while it hoes back on. Don't know what that could be. It turned off when I got home and when I put my code reader, it says no codes. I guess I have to catch it when it is on.
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Saturday, September 10th, 2022 AT 8:20 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Hi,

I didn't realize that I also, certainly, get it when it's on. Hopefully, that will help point us in the right direction. I know when this type of thing happens with my car, I plug it in before I even start the vehicle so I can test it as soon as the light turns on.

Let me know what you find.

Joe
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Saturday, September 10th, 2022 AT 9:28 PM
Tiny
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Will do. I will keep you posted. Thanks for all your help.
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Saturday, September 10th, 2022 AT 9:31 PM

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