Contents Section: Ignition System All sections

Ignition System - SOHC: Other Subaru Impreza GD/GC/GG рестайлинг

Ignition System 4 illustrations ~425 words

CAUTION

  1. Wear working clothing, including a cap, protective goggles, and protective shoes during operation.
  2. Remove contamination including dirt and corrosion before removal, installation or disassembly.
  3. Keep the disassembled parts in order and protect them from dust or dirt.
  4. Before removal, installation or disassembly, be sure to clarify the failure. Avoid unnecessary removal, installation, disassembly, and replacement.
  5. Be careful not to burn your hands, because each part on the vehicle is hot after running.
  6. Be sure to tighten fasteners including bolts and nuts to the specified torque.
  7. Place shop jacks or safety stands at the specified points.
  8. Before disconnecting electrical connectors of sensors or units, be sure to disconnect the ground cable from battery.

RH SIDE

Install in the reverse order of removal.

  1. Tightening torque (Spark plug): 21 N.m (2.1 kgf-m, 15.2 ft-lb)

Note. The above torque should be only applied to new spark plugs without oil on their threads. In case their threads are lubricated, the torque should be reduced by approximately 1/3 of the specified torque in order to avoid over-stressing.

LH SIDE

Install in the reverse order of removal.

  1. Tightening torque (Spark plug): 21 N.m (2.1 kgf-m, 15.2 ft-lb)

Note. The above torque should be only applied to new spark plugs without oil on their threads. In case their threads are lubricated, the torque should be reduced by approximately 1/3 of the specified torque in order to avoid over-stressing.

NORMAL

Brown to grayish-tan deposits and slight electrode wear indicates correct spark plug heat range.

Scheme 19

Scheme 19: NORMAL

CARBON FOULED

Dry fluffy carbon deposits on insulator and electrode are mostly caused by slow speed driving in city, weak ignition, too rich fuel mixture, dirty air cleaner, etc.

In this case, replace with plugs having a hotter heat range.

Scheme 20

Scheme 20: CARBON FOULED

OIL FOULED

Wet black deposits show excessive oil entrance into combustion chamber through worn rings and pistons or excessive clearance between valve guides and stems. If the same condition remains after repair, use a hotter plug.

Scheme 21

Scheme 21: OIL FOULED

OVERHEATING

White or light gray insulator with black or gray brown spots and bluish burnt electrodes indicates engine overheating. Moreover, the appearance results from incorrect ignition timing, loose spark plugs, wrong selection of fuel, hotter range plug, etc. In this case, replace with plugs having a hotter heat range.

Scheme 22

Scheme 22: OVERHEATING

CLEANING

Clean the spark plugs in a sand blast type cleaner.

Avoid excessive blasting. Clean and remove the carbon or oxide deposits. When doing this, do not wear away the ceramic part.

If deposits cannot be removed, replace the spark plugs.