1988 Chevrolet Spectrum ExpressFACTORY OEM SERVICE PROCEDURE

System Performance Check

  1. Set parking brake. Place transmission in "P" (A/T) or "N" (M/T) and block wheels. Start engine. Disconnect and plug vacuum hose from charcoal canister and vent switch valve. Connect tachometer. Disconnect feedback solenoid at 3-pin carburetor connector. Ground feedback solenoid dwell terminal.
  2. Run engine at 3000 RPM. Keep throttle constant and reconnect feedback solenoid. Note RPM. If RPM dropped more than 100 RPM, go to step 3). If RPM dropped less than 100 RPM or increased, check feedback solenoid connections or repair carburetor. Remove ground from feedback solenoid dwell terminal before returning to idle.
  3. Disconnect idle set connector and connect dwell meter (6 cyl. scale) to feedback solenoid dwell terminal. Warm engine at part throttle until upper radiator hose is warm. Return engine to idle and note dwell.
  4. If dwell is fixed less than 15 degrees, go to TEST 1  . If dwell is fixed at 15-50 degrees, go to TEST 2  . If dwell is fixed greater than 50 degrees, go to TEST 3  . If dwell is varying, go to step 5).
  5. Check dwell at 3000 RPM. If dwell is between 10-50 degrees, check fuel cut-off system in TEST 7. If dwell is not between 10-50 degrees, check TPS or repair carburetor. If no trouble found, clear trouble codes.
Factory Service Tools

Use the Manual With the Right Hardware

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

Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.

Shop Manual-Ready ToolsCompare Repair QuoteQuote Shield Pro

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.

Rather have a pro handle this?

A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.

Comes to youSame-day available12-month warranty
Get a Free Quote

No obligation. See pricing before you book.