Discussion:
backfire off idle underload

3.0 litre GM 4- cylinder LP-GAS--Impco-Spectrum fuel system- no codes-basics all checked-ran program on lap top-fuel controls OK--backfires through intake-underload off idle-no vac leaks-- fuel inlet hose from LP convertor OK-timing control-OK feedback from some folks, they say crank sensor? engine jerks like a wet dist cap-Cap,wires,rotor and plugs all new--initial timing set--OK --system simular to Yale but has crank sensor at front of engine, HELP! IF ANY ONE CAN HELP,IT WOULD BE GREATLY APPRECIATED THANKS
  • Posted 24 Jan 2008 12:52
  • Modified 25 Jan 2008 12:28 by poster
  • By roadrat
  • joined 24 Jan'08 - 186 messages
  • North Carolina, United States
Showing items 1 - 3 of 3 results.
good GM Vortec 3.0l 4 CYL No Radiator Has Muffler Natural Gas / Propane Engine
  • Posted 12 Oct 2018 19:39
  • By kahina_l
  • joined 12 Oct'18 - 3 messages
  • Algeria
You got there in the end, these GM engines have been bullet proof for us, but will keep in mind what you found.
  • Posted 7 Jul 2016 17:16
  • By luke_m
  • joined 2 Feb'13 - 97 messages
  • Bedfordshire, United Kingdom
After pain staking "check this and that" several times, call this one and that one ,We hit pay dirt---trigger wheel on harmonic balancer at front of engine was bent causing wheel to oscillate back and forth enough that sensor was not able to read the wheel causing signal loss.
  • Posted 1 Feb 2008 11:29
  • Modified 3 Mar 2008 22:23 by poster
  • By roadrat
  • joined 24 Jan'08 - 186 messages
  • North Carolina, United States

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