HEI Shielding

1987 Chevrolet Suburban R20, 5.7 K, StandardSECTION HEI Shielding

An open ground circuit may result in interference, or induced electrical "noise". The ECM looks at this "noise" as a reference pulse. The additional reference pulse results in higher than actual engine speed signal. The ECM then delivers too much fuel, causing the system to go rich. Engine tachometer will also show higher than actual engine speed which can help in diagnosing this problem.

RENDER: 1.0x

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.