Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
1987 Chevrolet Chevette L4-98 1.6LFACTORY OEM SERVICE PROCEDURE
Distributor Vacuum Control
Description and Operation- Distributor Spark Vacuum Modulator Valve (DS-VMV)
- Distributor Spark Vacuum Regulator Valve (DS-VRV)
- Distributor Thermal Control Valve (DTCV)
- Distributor Thermal Control Switch (DTCS)
- Distributor Vacuum Modulator Valve (DVMV)
- Electronic Module Retard-Vacuum Switch (EMR-VS)
- Vacuum Modulator Check Valve (VM-CV)
- Vacuum Reducer Valve
Testing and Inspection
Locations
Factory Service Tools
Use the Manual With the Right Hardware
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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.