ENGINE SURGES, IDLES HIGH, AND STARTS TO JERK HARD AND A WHINING NOISE FROM INSIDE THE MOTOR

  • Tiny
  • CLKeele
  • 2000 Chevrolet Impala
  • 200,100 miles

I have posted information about this problem before and although I did receive help unfortunately it did not fix my problem.

I have a 2000 Chevrolet Impala with a 3.8V6. When pulling away from a stop or just simply when I start to accelerate my car will suddenly surge repeatedly. This does not go away until I reach roughly 65mph. The problem is I have replaced many many things lately and nothing has fixed the problem. Initially my car was throwing code P0171b which indicated a lean bank. The problem is I have replaced all my vacuum lines, both 02 sensors, the catalytic converter, the MAF, the MAP, the TPS, the IAC and most recently just replaced my valve cover and intake manifold gaskets. The problem is still there. I have had all these repairs done within the last 5000 miles of my cars life. The problem now is my Air Bag light stays on, along with low coolant which I know is not an issue. Along with this the car still surges. I dont know what to do now as I have no clue where to go to troubleshoot it as the codes are gone besides the air bag, I can find no evidence of leaks of any kind either. I have taken this car to multiple mechanics who have no idea one of which whom is a personal friend is at a loss at this point. Can someone give me any ideas?

Friday, May 18th, 2012 AT 9:21 PM

7 Answers

  • Tiny
  • CLKeele
  • Member

Also just to let you know the fuel inectors along with the fuel pressure has been checked and cleaned and all is fine there also.

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Friday, May 18th, 2012 AT 10:23 PM
  • Tiny
  • hmac300
  • Expert
  • 42,082 posts

Try cleaning the throttle plate with choke cleaner on both sides. If you air bag light is on, you need apro to check it to see what is wrong setting it. What were the injectors cleaned with a pro type cleaner or just off the shelf stuff? Pro tpe needs to be put right into injector rail with fp off. Is it still throwing the codes?

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Friday, May 18th, 2012 AT 10:51 PM
  • Tiny
  • CLKeele
  • Member

They were cleaned with GM Top Cleaner, the codes have yet to return. I actually already cleaned the throttle body when I had it off replacing the intake gaskets.

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Friday, May 18th, 2012 AT 10:54 PM
  • Tiny
  • ASEMaster6371
  • Expert
  • 25,502 posts

I agree with Hmac about the injectors. Gm top engine cleans the plenums not the injectors.

Roy

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Friday, May 18th, 2012 AT 11:48 PM
  • Tiny
  • hmac300
  • Expert
  • 42,082 posts

Oh your whining noise may be your alternator as well. Also spray the belt with water and see if any noises disappear. If it doesn'it probably is time for a new belt and tensioner.

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Saturday, May 19th, 2012 AT 12:11 AM
  • Tiny
  • CLKeele
  • Member

I really appreciate all the help. Unfortunately my problem is still there and throwing the same p0171 code for lean/rich fuel. I know for fact that the car is running rich. The whining noise is coming from inside the engine which besides the point the belt and tensioner along with water pump and the harmonic balancer are all brand new. Im still lost. Because I just took it back to my mechanic and we used a pro fuel injector cleaner which hooked directly into the rails. Along with this issue now I seem to have sporadic electrical problems now like the lights dim occasionally when shifting or accelerating. The windows dont roll up or down now without the car being started. My question is could this be a computer related issue at this point. I have put way to much money in all of these other parts and it just seems more and more that I have a faulty computer which is also what my mechanic is starting to believe.

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Wednesday, June 6th, 2012 AT 9:00 PM
  • Tiny
  • hmac300
  • Expert
  • 42,082 posts

Check and clean your battery terminals and have the battery checked, it may be going bad. This still could be an injector problem as well. It could be a faulty computer or a bad connection there as well. I'm really out of ideas. What is the vacuum at idle?

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Wednesday, June 6th, 2012 AT 10:34 PM

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