High Altitude

1985 Toyota Pickup SR5, 2D Pickup, 4WDSECTION High Altitude
  1. Warm up engine and check ignition timing at idle. Disconnect hose from distributor sub-diaphragm, and plug hose end.
  2. Check ignition timing. Timing should be 5° BTDC. Reconnect hose to sub-diaphragm. Verify that timing advances to about 12° BTDC.
    Fig 1: HAC System
    G38379Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  3. Disconnect vacuum hose between check valve and vacuum pipe at vacuum pipe side. Plug pipe end.
  4. Disconnect 3 hoses from top of HAC valve. Blow air into each hose and check that air flows into carburetor. Reconnect hoses to proper locations.
RENDER: 1.0x

NO RELATED

Recommended Tools & Savings

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Affiliate disclosure: We may earn a commission at no extra cost to you.

When to See a Mechanic

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

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