Consistent Loss of Acceleration

Tiny
SMSVIDEO13
  • MEMBER
  • 1994 MERCURY TOPAZ
  • 2.3L
  • 4 CYL
  • AUTOMATIC
  • 466,000 MILES
I bought this car about a month ago. I pulled the codes and it had a P0158 for the MAF sensor. I replaced the MAF sensor, air filter, PCV, and fuel filter. I was on the freeway today and I noticed it was making this exaggerated revving sound after sixty mph. Then it slowly and consistently lost speed. I immediately got off the freeway in time to coast into the gas station as it cut off. Then when I tried to restart it, it will not turn over. Help!
Thursday, December 8th, 2016 AT 6:03 PM

11 Replies

Tiny
CARADIODOC
  • MECHANIC
  • 34,206 POSTS
If it isn't cranking, combined with the gradual loss of power, a failed charging system is the best suspect. Charge the battery at a slow rate for an hour, then try to start the engine. If the engine runs, measure the battery voltage with an inexpensive digital voltmeter. You must find between 13.75 and 14.7 volts. If it is low, suspect the generator, but there are a couple more tests we should do before you replace it.
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Friday, December 9th, 2016 AT 7:18 PM
Tiny
SMSVIDEO13
  • MEMBER
  • 6 POSTS
Hello, I got my battery tested and it failed horribly. So, I bought a new battery and I have also replaced the starter. It sounds like a normal crank but still will not start.
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Monday, December 19th, 2016 AT 11:25 AM
Tiny
STEVE W.
  • MECHANIC
  • 14,769 POSTS
Check for good fuel pressure. The low battery could have made the pump fail due to the increased current needed to keep it turning.
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Monday, December 19th, 2016 AT 12:18 PM
Tiny
SMSVIDEO13
  • MEMBER
  • 6 POSTS
Hello Steve. Thanks for the quick response. That can be a problem even if I can hear the pump? If so, how should I check?
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Monday, December 19th, 2016 AT 1:04 PM
Tiny
STEVE W.
  • MECHANIC
  • 14,769 POSTS
If you can hear the pump is should be turning, but it may not be turning fast enough. At least it would take one possible reason off the table. It's a fast test.
https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator
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Monday, December 19th, 2016 AT 6:43 PM
Tiny
SMSVIDEO13
  • MEMBER
  • 6 POSTS
Ok, I will check for that. I need to go buy the testing equipment. Here is a video of me trying to start the car. https://www.youtube.com/watch?v=jbMJi3TBUv4
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Saturday, January 7th, 2017 AT 12:24 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 52,273 POSTS
Hey SMSVIDEO13,

The video really helped out, it sounds like the engine is having a problem, please remove all spark plugs and do a compression test, here is a guide that will help you. If you don't have a compression gauge go the auto parts store and rent one, they are cheap, the stores here they don't even charge for it, here is a guide that will show you what to do, I wish everyone that had a problem would do a video makes our job much easier.

https://www.2carpros.com/articles/how-to-test-engine-compression

Please run this test and get back to us so we can continue helping you.

Best, Ken
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Wednesday, January 11th, 2017 AT 10:39 AM
Tiny
SMSVIDEO13
  • MEMBER
  • 6 POSTS
Thank you, Ken! I will go to the auto parts store this weekend to pick up what I need.
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Wednesday, January 11th, 2017 AT 10:43 AM
Tiny
STEVE W.
  • MECHANIC
  • 14,769 POSTS
What Ken is referring to in the video is that you can hear a large difference in the way each cylinder is effecting the cranking speed. Compression pressure difference is what is making it sound different. A compression test followed by a leak down test will give a good idea of the problem.

Many parts stores have a loan a tool or rental program so you don't have to buy tools you will use once. Most do it by selling you the tool and when you return it you get your money back.
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Wednesday, January 11th, 2017 AT 5:47 PM
Tiny
SMSVIDEO13
  • MEMBER
  • 6 POSTS
Well, I have got the car to start. It was the darn distributor. But after getting her started again I have a new sound. Yay! Let me know what you think. https://youtu.be/p2Ooeccexss
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Monday, March 20th, 2017 AT 7:44 AM
Tiny
STEVE W.
  • MECHANIC
  • 14,769 POSTS
That is not a good sound. Pull the accessory belt off and make sure it isn't something there first, but it sounds like rod bearings. Check the oil for glitter. The distributor drives the oil pump, did you make sure the drive shaft engaged the drive on the distributor? What was the issue with the old distributor? Drive gear ground down?
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Monday, March 20th, 2017 AT 1:58 PM

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