1993 Chevy Silverado Knock sensor

Tiny
JOHNBOY300
  • MEMBER
  • 1993 CHEVROLET SILVERADO
  • V8
  • 4WD
  • AUTOMATIC
  • 20,600 MILES
Fuel gauge went crazy, way past FULL. Then barely would run, would not idle without going dead. Had to pat accelerator and nurse it back home. Very young inexperienced tech replaced knock sensor and plug pigtail. Code still shows knock sensor problem.
Thursday, November 27th, 2008 AT 5:53 PM

5 Replies

Tiny
BLUELIGHTNIN6
  • MECHANIC
  • 16,542 POSTS
Sounds like a faulty fuel sending unit. Faulty sending unit will cause computer to get "confused" and not know how much fuel to actually send to engine, in return the engine is not getting the correct amount of fuel needed to run properly.

Disconnect battery for 10 minutes then reconnect. This will reset the engine light. If it comes on again have it scanned again and post your results.
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Thursday, November 27th, 2008 AT 6:05 PM
Tiny
JOHNBOY300
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  • 3 POSTS
Replaced fuel pump approx. 5 yrs ago, but less than 2000 miles ago since this trucks sits most of the time. Still think it is the fuel pump? I'm assuming sending unit and fuel pump are the same item?
Thanks,
John
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Thursday, November 27th, 2008 AT 6:30 PM
Tiny
BLUELIGHTNIN6
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The sending unit is the unit that sends message to computer for proper gauge reading & fuel amount. The fuel pump is the pump itself that delivers fuel through the system.
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Thursday, November 27th, 2008 AT 7:09 PM
Tiny
JOHNBOY300
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Have now replaced knock sensor and pigtail, fuel pump and sending unit. Trucks runs good now, but check engine light is still on and code still shows problem with knock sensor. What do you recommend? Thanks for your help.
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Wednesday, December 10th, 2008 AT 11:25 AM
Tiny
BLUELIGHTNIN6
  • MECHANIC
  • 16,542 POSTS
Take it to a local auto part store such as AutoZone or O'Reilly Auto Part to have code deleted using the same scanner tool that gives you the codes. Normally they will not go out on their own just becuase you fix the issue, they have to be reset. You can also just disconnect neg. Cable on battery for 10 minutes or longer but this can also reset other things that you don't want reset, such as radio settings, clocks, etc.
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+1
Wednesday, December 10th, 2008 AT 11:30 AM

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