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 MANUALSCHEVROLET1987CAPRICE CLASSIC, 4D WAGONREPAIR AND DIAGNOSIS (SINGLE PAGE)ENGINE PERFORMANCEIGNITION SYSTEM - HEI-ESTTESTINGINTERMITTENT OPERATION CHECK
1987 Chevrolet Caprice Classic, 4D Wagon
Intermittent Operation Check
1987 Chevrolet Caprice Classic, 4D WagonSECTION Intermittent Operation Check
- Connect Spark Tester (ST-125) to 2 different spark plug wires. If no spark, go to Ignition System Check. If spark is present on either or both wires, check for dwell increase from low to high RPM.
- Check pick-up coil and Hall Effect switch (if equipped). Replace if faulty. If pick-up coil and Hall Effect switch are good, and dwell did not increase, replace HEI (EST) module. If pick-up coil and Hall Effect switch are good, and dwell increased, check fuel system, spark plug wires, distributor cap, and spark plugs.
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.