1994 Chevy Blazer rough running, surging, hunting idle

1994 CHEVROLET BLAZER
121,000 MILES • 6 CYL • 4WD • AUTOMATIC
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SHARPKAT79
  • MEMBER
  • 17 POSTS
'94 t-10 blazer it has a rough idle and it also will race up to around 2000 rpms and drops down around the normal idle speed and almost stalls then raises high again. the fuel trims are showing rich because it is subtracting fuel. all the sensors have the proper voltage and/or numbers. then when u make a vaccume leak the fuel trims go in the opposite direction or just dont move
Feb 10, 2010 at 5:30 AM
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JACOBANDNICKOLAS
  • ✓Experienced Mechanic
  • 110,248 POSTS
When you create a vacuum leak, it will lean out. That is normal because you are allowing more fresh air to enter the engine. Does the engine smooth out when you create a vacuum leak? Have you checked the fuel pressure and regulator?
Feb 17, 2010 at 3:22 AM
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SHARPKAT79
  • MEMBER
  • 17 POSTS
the fuel trims dont change but it doesnt change when i make a vaccume leak and im gonna be checking the fuel pressure on monday when i change the water pump
Feb 19, 2010 at 9:16 AM
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SHARPKAT79
  • MEMBER
  • 17 POSTS
i figured out wat the problem was and i wast about ready to put a new or even used computer in something that is 900 bucks, but that was the problem and im 99.9% on that was the problem
Mar 12, 2010 at 10:57 AM
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