What happens if there is no voltage in the HEI distributor?
What happens if there is no voltage in the HEI distributor?
If the positive hot wire from the battery that feeds the distributor has no voltage to it, the HEI distributor will not function. The starter will crank the engine but there will be no fire coming from any of the spark plug wires or spark plugs.
When did the GM HEI ignition distributor come out?
Great Performance, Affordable Cost! GM’s high energy ignition (HEI) distributor has been used as an affordable, easy to install performance distributor since its introduction in the mid 70s. It should come as no surprise being one of the most popular options among modern rodders and race enthusiasts to this day.
Is the ignition coil inside the distributor cap?
Most of the original GM V-6 and V-8 models used an ignition coil inside the distributor cap, making it a one-piece ready-to-run distributor. HEI ignition systems are very dependable and offer great performance on a number of applications.
What happens when a Hei plug goes bad?
Plug wires that measure “infinity” have broken connections. The HEI system controls the spark timing changes for the engine, which regulates emissions, engine performance and fuel economy. Any reduction in fuel economy can indicate the electronic spark timing (EST) in the HEI control system has failed.
What should the voltage be on a HEI distributor?
Disconnect the green and white wires from the module and touch the positive meter lead to the green wire and the negative lead to the white wire. The normal reading should be between 800 – 910 ohms. Testing the primary circuit of the coil. The remaining electronic part that would keep the distributor from firing is the module.
How can I tell if my HEI distributor is bad?
When checking for 12 volts, do so while you are cranking the engine. If the battery voltage drops below 10.5 volts while cranking, you probably have a bad battery. This low voltage could be insufficient to get the distributor to fire. Use a volt meter to test the hot wire while a buddy cranks the engine over.
Why do spark plugs not work with distributor cap?
Here’s why: As the distributor cap ages, the terminals that transmit the spark to the spark plug wires corrode. This corrosion increases the resistance to spark and over time (as more corrosion is created) this same corrosion stops the spark from passing thru’ to the spark plug wires.
What to do when your HEI distributor starts to fire?
If the battery is fine, make sure the wire feeding the distributor is sufficient. To make sure it is not the hot wire, run a temporary jumper wire directly from the positive side of the battery to the distributor. If the distributor fires using the jumper wire, run a new hot wire from your switched 12-volt source to the distributor.
What to do if your GM HEI distributor is not working?
If the coil is good, the cap and rotor are not cracked or worn significantly and there is no spark at any wire, replace the ignition module. Hook up an advance timing light by hooking the carbon connection over the No. 1 cylinder wire and hook the positive and negative clips to the battery.
What does a yellow Spark on a HEI distributor mean?
A yellow or intermittent spark indicates weak HEI coil output. Examining the HEI distributor at night with the hood up can pinpoint any stray electrical arcing from the cap, wire connections, distributor cap retainer and connector terminals.
Where does the power wire come from on a Hei?
There is no longer a need for the power wire that comes from the starter “R” terminal. On most HEI’s, there are three wires that come from the base of the distributor and they plug into the cap. It’s a connector block and can’t be plugged in wrong. DISTRIBUTORS & HEI INSTALLATIONS Page 9 Identifying your HEI system
How can I tell if my HEI distributor is still running?
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. The reading should be infinity. Check the coil tower and the negative terminal. The reading should be 900 ohms. Check the positive terminal to the negative terminal.
How does a GM HEI distributor work on a car?
The GM HEI distributor uses a hall effect for the triggering and sensing the No.1 cylinder location and the rpm of the engine. It uses an ignition module within the distributor to regulate the timing curve as well. It will automatically advance the timing on acceleration a specific amount and retard the spark when decelerating and starting.
Can a Hei coil be tested with an ohm meter?
Testing the HEI coil used to be OK with only an ohm meter, but not today. Load testing the coil off the distributor, on a machine designed to do so, IS the right, and only way to test them. If the module is bad, then I would seriously think the coil (s) were responsible for the module going out.
