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Do HEI distributors go bad?
99 percent of the time, in the large, coil in cap HEI’s, it ISN’T the module “just going bad”, or even “getting weak”. The real problem is the coil degrading gradually, failure process called “layer shorting”, which rarely causes the module to go way gradually.
How do I test my HEI pickup?
To test the pickup coil, unhook the two terminals carefully, test each one to see that they’re not grounded by hooking one tester lead to the wire, the other to ground. There should be infinite resistance. Now check between both wires.
Is a HEI distributor magnetic?
The High Energy Ignition (HEI) used on most General Motors products prior to the use of fuel injection was a hall effect type of distributor. It did away with the conventional points and condenser and used a magnetic pickup. The control unit for the magnetic pickup is a module located in the distributor.
Are HEI distributors good?
An HEI distributor is a great piece of equipment for an over-the-road car because it is completely self-contained. It requires minimal wiring and is easy to install. But without an external coil, a stock HEI cannot provide a strong spark at rpm levels commonly seen on the racetrack.
How do I know if my distributor 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.
How do you test a distributor pickup?
On distributors with the pickup separate from the module assembly, you can check the pickup using your Ohm meter. Connect the leads from your Ohm meter to the 2 leads of the pickup. If you show a resistance of 50 to 200 Ohms, the pickup is functioning correctly.
How do you test a Hei performance distributor?
To test for a good ground, a jumper wire can be attached to the distributor by connecting it anywhere on the housing and running it to the negative side of the battery. If all of that checks out, the following steps will help you to test the coil inside the cap, and the magnetic pick up.
How do I Test my GM Hei module?
Testing the 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.
What are the colors of the HEI distributor?
On a factory HEI, the primary coil leads will either be white and red, or yellow and red. The colors of the leads determine the direction the coil is wound, which determines its polarity. Whenever you are replacing a coil or distributor, it’s always a good idea to be sure to the ground clip is transferred from the old cap to the new.
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.