Table of Contents
How do I know if my HEI module is bad?
Bad HEI ignition distributors give off some warning signs that can be diagnosed by the vehicle owner.
- Engine Fails to Start.
- Plug Wire Engine Miss.
- Reduced Fuel Economy.
- Weak Spark.
- Electrical Arc and Shorts.
- Hard Starting.
- Smog Check Failure.
How do you test a Ignition Control Module?
Connect the ground lead from the 12-volt test light to the negative terminal on the ignition coil. Have your partner crank the engine over several times. Your test light should flicker on and off. If so, your module is working properly and no further testing is necessary.
How do you troubleshoot a GM HEI distributor?
Check the rotor and the cap for excessive wear. Check the coil tower for excessive wear. Remove the top plastic cap on the distributor cap. Use an ohmmeter and check the coil positive terminal to the metal case of the coil.
How many ohms should a ignition coil have?
The meter should read between approximately 0.4 and 2 ohms. If it does not, the coil’s primary winding is faulty.
How can you tell if a pickup coil is bad?
Signs of a Bad Pickup Coil
- No Engine Spark. The pickup coil sends the signal from the ignition module to the spark plugs during the ignition process.
- Rough Idle. Because the spark plugs are not communicating proper timing to the fuel injectors, a rough idle may occur.
- Engine Stall/Failure to Accelerate.
Can you test a pickup coil?
Connect the red (positive) lead of the multimeter to the outer, positive terminal of the ignition coil. Turn the reading dial on the multimeter to ohms to measure resistance of the primary pickup coil. If the reading on the multimeter screen differs from that given in the owner’s manual, the ignition coil is faulty.
How do you test HEI?
How To Test an HEI distributor Engine Cranks But Will Not Start
- With the ignition on, connect a voltmeter (or test light) to the + post or HEI BAT terminal located on the distributor cap.
- Check for continuity or voltage drop in the ignition switch and in the circuit from the switch to HEI BAT terminal.
How do you test a ignition module on a Chevy?
If your GM vehicle has a slow or hard start, the ignition control module should be tested with an electrical test light.
- Open the hood of the GM vehicle. Locate the ignition module.
- Connect the positive test light lead to the ignition module signal wire.
- Ask a partner to crank the engine numerous times.
What are the signs of a bad ignition module?
Symptoms of a bad ignition module are sudden engine stalling or power loss while the car is in motion, engine stuttering accompanied by a smell of gasoline and an inability to restart the engine following a stall. Decreased gas mileage is also a sign of a compromised ignition module.
What causes ignition modules to fail?
Because the ignition module is electronic and does not utilize moving components, it is normally one of the most reliable part of the engine. When it does fail, it is usually due to heat caused from improper wiring of the ground wire to battery voltage.
How to test ignition coils?
Swapping Coils. Swapping the ignition coil with another known,good unit on the car is the easiest and simplest way to begin diagnosis and works extremely well on any vehicle