Vacuum Leaks Ususal Suspects

Tiny
CHRISPASSEY1
  • 1999 GMC SIERRA
  • V8
  • 2WD
  • AUTOMATIC
  • 210,000 MILES

I am having real trouble with my Truck. I keep on hearing from mechanics and other knowledgable people that my problem could be because of Vacuum leaks in the Engine.
Now I understand (basically) the theroy of what they are getting at, but could someone tell me what they specifically mean? Also, could you tell me where in the Engine should I look and how many places are there where the seal could be leaking?
I guess what I am asking is who are the usual suspects?
Finally, is there any place online where I can see a picture (system diagram) of what they are talking about?

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Wednesday, December 8th, 2010 AT 5:43 PM

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Tiny
DENNYP
  • EXPERT
  • 1,870 POSTS

What is the problem you are having?

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Wednesday, December 8th, 2010 AT 8:04 PM
Tiny
CHRISPASSEY1
  • MEMBER

The problem is that the Truck is stalling at a stop and it idling poorly. It almost sounds like it is choaking. I have replaced the Mass air filter, the spark plugs and ignition coils (I am not sure if the last two would be the cause) and I am hoping it isn't the catalytic converter. So before I hit that point, I decided to ask around and everyone I ask says it could be a vacuum leak. I just don't really know where to start.

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Wednesday, December 8th, 2010 AT 9:38 PM
Tiny
DENNYP
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Start off by having it scanned for any trouble codes. If you don't have any codes, try cleaning the throttle body.
Use some throttle body cleaner and a toothbrush to scrub the carbon out of the inside of the throttle body opening.
Let me know if this helps.

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Thursday, December 9th, 2010 AT 1:36 AM
Tiny
CHRISPASSEY1
  • MEMBER

Thanks,
I will do that tonight and get back to you.

Thanks dennyp!

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Thursday, December 9th, 2010 AT 2:40 PM

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