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Home >> Porsche >> 1985 >> 928 Standard >> Repair and Diagnosis >> Engine Performance >> System >> Fuel Injection System - BOSCH LH >> Testing >> Test 1 >> Checking Ground & Plug Connections
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Checking Ground & Plug Connections

  1. Check engine ground between body and engine at bottom right. Check ignition control unit ground at left front and ground on front end on right side. Check ground located on crankcase bell housing on left side below fuel return line (control unit and oxygen heating unit).
  2. Check ground on crankcase bell housing on right side below fuel return line. Check ground connection on hot wire, throttle switch, injection control unit, EZF control unit, test connector and oxygen sensor shield. Check ground point in front of right ignition coil (ignition trigger box).
  3. Check plug connections on relays 16, 20 and 25. Check plug connection on central electric board (CEB) of plug (W 4). Check 25-pin connectors for LH and EZF control units. Check 6-pin plug on air mass sensor.
  4. Check 3-pin plug on throttle switch and in front of test connector 3-pin adapter plug. Check 2-pin plugs on temperature sensors I and II. Check 3-pin plug on speed/reference mark sensor. Check fuel injector connections.
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