wont idle have 2 pump gas pedal 2 keep it running

1994 CHEVROLET SILVERADO
252,000 MILES
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JARET
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  • 1 POST
94 7.3 backfires through tb, replaced map sensor, tps, fuel pump, cap& rotor , wires truck is a 1 ton with 7.3
Nov 16, 2011 at 11:52 PM
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ASEMASTER6371
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  • 52,796 POSTS
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sounds like the camshaft has worn out. common on the old engines. soft material and when they wear out, they backfire through the throttle body.

this is assuming your plugs, wires, cap and rotor are all good.

Roy
Nov 16, 2011 at 11:55 PM
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RASMATAZ
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  • 75,992 POSTS
  • ASE Certified Mechanic
If it comes down to the camshaft best replace the valve lifters too-their partners in crime-they work as a team-same goes with the cap and rotor on conventional ignition system-
Nov 17, 2011 at 12:04 AM
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