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.
SYS.OK|MANUAL.DB● LIVE
HOMESERVICE MANUALSCHEVROLET1987NOVA BASE, 4D SEDAN, AUTOMATICREPAIR AND DIAGNOSIS (SINGLE PAGE)ENGINE PERFORMANCETESTING & DIAGNOSISEGR FUNCTION TESTINGVACUUM CONTROLMODULATOR VALVE
1987 Chevrolet Nova Base, 4D Sedan, Automatic
Modulator Valve
1987 Chevrolet Nova Base, 4D Sedan, AutomaticSECTION Modulator Valve
- Disconnect all vacuum and exhaust pipe hoses from modulator valve. Cap fittings going to each EGR control solenoid. Blow into bottom fitting from exhaust pipe end.
- Apply 7 in. Hg to fitting No. 3 (from ported vacuum source). Vacuum should hold until pressure at bottom fitting is released. If further testing is required, see SYSTEM & COMPONENT TESTING article in ENGINE PERFORMANCE section.
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.