Loss of power when accelerating

Tiny
SGREENWOOD
  • MEMBER
  • 2003 CHEVROLET TRAILBLAZER
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 112,000 MILES
Drives fine on level ground, but when accelerate uphill, loses power. Engine remains on, but no power. Engine light on, but have not run codes yet.
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Wednesday, February 9th, 2011 AT 7:33 PM

25 Replies

Tiny
RASMATAZ
  • MEMBER
Hello,

Lets run the codes by following this guide. Will will probable give you a mixture or fuel trim codes which will indicate and bad fuel pump.

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

Here is a guide to show you what you must do to replace the fuel pump with diagrams below to help you see how it will be for your car.

https://www.2carpros.com/articles/how-to-replace-an-electric-fuel-pump

Check out the diagrams (below). Please let us know what you find.

Cheers
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Thursday, March 10th, 2011 AT 2:22 AM
Tiny
THOMO
  • MEMBER
Thanks for this post. I got a pump for $210.00 on Amazon and it took a day but I got it done runs great! I love this site.
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Friday, September 7th, 2018 AT 5:47 PM
Tiny
DALANDA MONTGOMERY
  • MEMBER
  • 2003 CHEVROLET TRAILBLAZER
My truck was riding fine on a trip suddenly we started to lose power. We pressed on the gas pedal and it seemed like the care kept slowing down. No indicator lights came on, we pulled over to a rest area and let the car cool off started off again regained power for about five miles and then the same thing happened again a loss of power, at this time the service engine light came on. I had the car towed to my house where it has sat for two weeks. I am not sure what the problem is. We had put some oil in before we left on the trip because it was low I have only had this truck for about three months and before I chuck out any more cash I would like to get an idea of what to ask when I go to a repair person because I have been burned by mechanics before (I am a female). Please help me if you can with my problem and help me avoid being taken advantage of again I am on a very tight budget and I miss driving my car. Thank you in advance for your help.
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Friday, September 7th, 2018 AT 5:48 PM (Merged)
Tiny
JACOBANDNICKOLAS
  • EXPERT
First, it is a good thing that the check engine light came on. What needs to be done is to have the computer scanned to determine what trouble codes are stored in the computer. Most parts stores will do it for free; however, since you cannot drive it, that is a problem. You need to get a scanner to use to check for codes. If there are any nationally recognized parts stores near you (Auto Zone, Advance) call and ask if they lend scanners.

I have to be honest, based on your description, it sounds like the fuel pump has stopped working. I know a parts store will lend you a fuel pressure gauge which is all you need.

Here is a link to an article from this site with step by step instructions and pictures explaining the process of checking the fuel system pressure, regulator and fuel pump in less than fifteen minutes:

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

Let me know what you find. I will help you through this.
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Friday, September 7th, 2018 AT 5:48 PM (Merged)
Tiny
DEBBID
  • MEMBER
  • 2003 CHEVROLET TRAILBLAZER
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 129,000 MILES
I just put in a new alternator and now when I turn on the air conditioning I lose rpm's and it will shut off when I am at a stoplight or in idle. When the AC is off I do not have a problem. What could be the problem?
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Friday, September 7th, 2018 AT 5:48 PM (Merged)
Tiny
PROTECH1980
  • EXPERT
Was the battery disconnected? If so clean the throttle body bore and the throttle valve plate using a toothbrush and approved throttle body cleaner then retry. This should fix your problem.
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Friday, September 7th, 2018 AT 5:48 PM (Merged)
Tiny
SQUEETZ
  • MEMBER
  • 2003 CHEVROLET TRAILBLAZER
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 78,800 MILES
My vehicle has started to roar when accelerating or on occasion starting up. This happened quite awhile ago but stopped now it seems to do it every day. Cannot seem to find a common connection as to when or why I can it expect it. Is this transmission? Hope not. Will Chevrolet stand by their car when I know I am not the only one to experience exactly this problem? In fact way too many people have posted on this subject.
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Friday, September 7th, 2018 AT 5:48 PM (Merged)
Tiny
DENNYP
  • EXPERT
It sounds like a bad fan clutch on the engine. It is a common failure, but the vehicle has over 78,000 on it. The vehicle warranty is only good to 36,000. It is always a good idea to purchase a good extended warranty on any new vehicle you plan on keeping past the original warranty period.
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Friday, September 7th, 2018 AT 5:48 PM (Merged)
Tiny
91RACKER
  • MEMBER
  • 2003 CHEVROLET TRAILBLAZER
  • V8
  • 2WD
  • AUTOMATIC
  • 82,000 MILES
I recently replaced the fan clutch myself after getting the jet-engine noise and then the TB worked great. I have not gotten the PCM updates from the dealer yet. The TB now loses power and (Reduced Engine Power) light comes on. The vehicle blows black smoke and leaks water from exhaust. The car will not start now.

Took the TB to autozone and got code P1518 Electronic throttle module to PCM Communication.

Also message that IMRC stuck open and damage to INRC actuator. Could the problem be from needing PCM updates, or might it need a new (TPS) Throttle body Position Sensor?
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Friday, September 7th, 2018 AT 5:48 PM (Merged)
Tiny
MMPRINCE4000
  • EXPERT
I believe this model uses an Accelerator Pedal Position Sensor Assy.

Usually GM cars will set a default value to a sensor that has failed. This value is usually rich to prevent a lean condition that can melt pistons and other bad things.

That would explain the black smoke (rich). You want to fix this because a rich condition will eventually melt the convertor.

Have GM diagnose the problem, or use the car repair manual link in this thread or get a Haynes manual.

If the Accelerator Pedal Position Sensor Assy. Is not sending the correct signal to the PCM it is probably the problem.

Thanks for the donation, it is appreciated.
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Friday, September 7th, 2018 AT 5:48 PM (Merged)
Tiny
JULES12
  • MEMBER
  • 2003 CHEVROLET TRAILBLAZER
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 114,400 MILES
I took my vehicle in to get checked last month cause the check engine light was on. It really was not running too bad at times it felt a little sluggish when accelerating and for a while before the check engine light went on and stayed on it only came on when it rained. I was never able to take it in to get looked at because when I could get to the repair shop it would stop raining and the check engine light would go off. Well they looked at it and they replaced the coolant and housing (I am not exactly sure what this means I am copying this off the bill) and the did a fuel injection service and throttle body service. For a few days everything was okay, but then it started shaking when I would turn off my truck and also when it would idle. It is very slow to accelerate much much worse than it was before. Before it was not that noticeable. And it seems the fuel economy is a little worse. It has stalled out once or twice but it turns right back on. Please help
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Friday, September 7th, 2018 AT 5:48 PM (Merged)
Tiny
MERLIN2021
  • EXPERT
You may have a vacuum leak, get a can of spray Gumout, spray the vacuum lines and manifold area, when the idle changes, you have found the leak! You want the engine running and spray on the outside but do direct the stream onto the hoses, if it is a vacuum leak, the engine idle will change speed, then you have detected a leak, repair the vacuum leak and see how it runs! Or it could be the idle air control valve, if most of the trouble is at idle and take off. It is bolted to the throttle body, is the service engine light coming on? Have the codes read?

Here is a link to an article from this site that features written step by step instructions and pictures explaining how to do the scan 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

Post the results with the code number(s). Even if the service engine light is not on, there should be freeze frame data stored.
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Friday, September 7th, 2018 AT 5:48 PM (Merged)
Tiny
DREMXNROE
  • MEMBER
  • 2003 CHEVROLET TRAILBLAZER
  • 4.2L
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 168,234 MILES
Hello, I have a big problem. There is a small hose that sits under the Votec Box. It is on the left hand side, on the bottom and in the front but right under the Vortec box. Is this causing my car to shake, lose power because I was only go no more than thirty miles per hour? Before I found this sliced hose my car was shaking very bad. I used a car reader and it said a misfire on number one. Also, it said that my fan was very high. I am not sure if I make sense but I would gladly send pictures.
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Friday, September 7th, 2018 AT 5:48 PM (Merged)
Tiny
STEVE W.
  • EXPERT
Pictures would help, you can upload them using the add image button?

It would depend on what the hose does as to its effect on the engine. It sounds like it could be a vacuum hose. A large vacuum leak can cause many issues.

What were the codes the reader gave you?
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Friday, September 7th, 2018 AT 5:48 PM (Merged)
Tiny
DREMXNROE
  • MEMBER
Where my fingernail is.
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Friday, September 7th, 2018 AT 5:48 PM (Merged)
Tiny
DREMXNROE
  • MEMBER
The codes were P0301 and P0495.
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Friday, September 7th, 2018 AT 5:48 PM (Merged)
Tiny
STEVE W.
  • EXPERT
Okay, that is the crankcase vent for the PCV system and it can easily cause a misfire because it pulls in air that the computer does not "see" with its sensors. It attaches under the lip of the resonator box in a grommet. (See arrow) It looks like you may need to remove the resonator, clean and replace the grommet to get it to stay because it appears to be loose if it pulled out.

That could easily cause the P0301.

P0495 - Cooling Fan High Speed. This is a semi common code on these, It means the cooling fan clutch is failing/failed. A quick test to determine if the clutch is failed would be to open the hood, start the engine, and shut it off, if the fan does no keep spinning a bit after the engine is shut off but instead stops with the engine, the clutch is locked. Another is to try turning the fan immediately after you shut it off. You can still drive it but it will be noisy and will keep the CEL and can cause unwanted wear on other parts.
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Friday, September 7th, 2018 AT 5:48 PM (Merged)
Tiny
GANDHIG21
  • MEMBER
  • 2003 CHEVROLET TRAILBLAZER
  • 6 CYL
  • AWD
  • AUTOMATIC
  • 105,965 MILES
I have read a lot of problems on the net with them. I bought it two months ago used from a dealer. Recently in the past couple weeks I have noticed that when I get on the gas and any speed the truck seems to hesitate all the way through accelerating and even at steady speeds on the highway. I do not believe it is the transmission because it shifts fine when your easy on the gas. Just seems like it has a lack of power. It is not throwing any check engine lights. What could this be?
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Friday, September 7th, 2018 AT 5:48 PM (Merged)
Tiny
BMRFIXIT
  • EXPERT
With the mileage you have listed I would suggest to check it for tune up.
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Friday, September 7th, 2018 AT 5:48 PM (Merged)
Tiny
DREMXNROE
  • MEMBER
Wow, thank you so much. I am definitely recommending you guys. May I share you guys on my Facebook?
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Friday, September 7th, 2018 AT 5:48 PM (Merged)

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