What does the HEI ignition module do? The key functions for the HEI module are to set the current limits for the ignition and establish the dwell circuitry. High-performance modules like the ACCEL, MSD, Performance Distributors, and Pertronix units allow higher current limits and increased dwell time at high rpm.
Is there a way to test a Hei module?
for the HEI gurus, does this look like a good way to diagnose HEI issues? "The easiest way to test a module on the car is to ensure that the wiring & pickup coil are OK. The module is essentially an amplifier with a built in analog to digital convertor. Easy tests for HEI system:
What are the symptoms of a bad ignition module?
Popular GM Ignition Control Module
- Chevy Ignition Module Failure 1996 through 2005. In 1996 General Motors redesign the ignition module discussed above. ...
- Ignition Module Control Unit for Direct Ignition. In the early 90s General Motors started to do away with the distributor, cap and rotor we all loved since the turn-of-the-century.
- Final Thoughts about Ignition Control Module Failure. ...
How do you set timing on Hei engine?
PROCEDURE:Set timing under the following conditions:
- Normal operating temperature.
- Air cleaner installed.
- A/C "OFF".
- Transmission in neutral.
- Disconnect SET TIMING connector (tan/black wire) located in harness close to distributor. DO NOT disconnect 4 wire connector at distributor.
What exactly is the job of a "ignition module"?
An ignition module is the component in electronic ignition systems that functions as the contact breaker for the coil or coils. In most basic terms, an ignition module is an electronic replacement for old, mechanical contact breakers like ignition points.
What are the symptoms of a faulty ignition module?
stalling: a failing ignition module can occasionally prevent the engine from getting spark, causing it to stall. 4. car won't start: an engine needs four basic things to run: fuel,compression, spark and exhaust. if the ignition module has failed completely, the vehicle won't get spark and won't start.Apr 26, 2018
Does HEI ignition add horsepower?
0:377:31HEI Ignition Tips for Your Engine - YouTubeYouTubeStart of suggested clipEnd of suggested clipOr the RPM levels. Performance distributors does this by including a 50,000 volt coil inside the catMoreOr the RPM levels. Performance distributors does this by including a 50,000 volt coil inside the cat that produces one long duration spark they say this increases both throttle response and low-end.
What does a HEI distributor do?
HEI distributors are a popular swap on older GM cars originally equipped with points and condenser type ignition systems. The HEI system produces a more powerful spark, which allows for a wider spark plug gap for surer ignition of a fuel/air mix that may not be optimal.
How do you check HEI ignition control module?
Easy tests for HEI system:Test for power at the pink BAT terminal. You should have battery voltage w/ the key in the start and RUN positions.Connect the ground side of your test lamp to the battery POSITIVE cable. ... Remove the cap & rotor. ... DVOM (meter) still connected to green & white leads.Jun 10, 2012
Why is HEI better than points?
The first is reliability, as electronic ignitions are virtually maintenance free. Also, HEIs allow full alternator voltage to go through the ignition system, which with our 50,000-volt coil allows larger plug gaps for better combustion and more power.Dec 1, 1998
Does HEI distributor need ballast resistor?
When using HEI, the distributor requires a 12 volt feed. In order to achieve this the ballast resistor or the resistance wire must be removed from the circuit and replaced with a pure 12 gauge feed wire.
What does HEI ignition stand for?
High Energy IgnitionHEI stands for “High Energy Ignition” or, Electronic Ignition. It can replace “points type” ignitions. This covers a broad range of automotive manufactures and companies that make this type of distributor system. When American Autowire refers to HEI, we are referring to GM 1974 – 1980 Large Distributor Cap design*.
What does a HEI distributor need?
The separate coil also requires low-tension and high-tension hookups to the distributor. In order to run properly, an HEI requires a full 12 volts at all times. The 20-gauge resistance wire must be replaced by a 12-gauge wire (pink to maintain the factory colour coding), hooked up to the HEI cap's "BAT" terminal.
What year did GM start using HEI ignition?
General Motor's HEI distributors are still going strong. GM's High energy ignition (HEI), designed and built by the Delco-Remy division of General Motors starting in 1974. These units were used on all engines in 1975 through the mid-1980s, with several different variations over the years.Apr 18, 2014
How do you test HEI to pick up a coil?
8:1014:19HEI Distributor Pickup Coil Test - YouTubeYouTubeStart of suggested clipEnd of suggested clipThis back in now you can usually just disconnect this and then put your probes on this connectorMoreThis back in now you can usually just disconnect this and then put your probes on this connector where the two metal. Contacts. Are inside that right. So either way you do it should come up the same.
How do you troubleshoot a 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 do you test a GM ignition Control Module?
Clip the negative test light lead to a solid ground such as negative battery terminal. Ask a partner to crank the engine numerous times. The test light should turn on and off as the ignition control module is signaled. If no light is preset, the module is faulty and needs to be replaced.
What is HEI distributor?
The HEI distributor is still an inductive-discharge ignition, but exchanges points for an electronic device called a module. Since this system produces more voltage and amperage output than a point-type ignition, it requires a larger-diameter cap to prevent voltage crossfire inside the distributor cap.
Why are Hei coils cooler?
HEI Coils also run cooler because they are encapsulated in thermal epoxy, which dissipates heat more efficiently than oil-filled coils. The solid epoxy, in comparison to oil-filled coils also eliminates the possibility of leaks.
What speed does a Hei distributor give up?
Early HEIs were infamous for giving up at speeds above 5,000 rpm-so many avoided them. This was true of the early-model distributors, but it didn't take GM long to modify the modules and coils to offer greatly increased spark energy at higher engine speeds. These days there's a plethora of aftermarket high-performance modules, coils, and complete ready-to-run HEI distributors that can be added to a high-performance engine that'll provide excellent spark energy and rpm potential well in excess of 7,000 rpm.
Does vacuum advance increase horsepower?
Vacuum advance doesn't lead to more horsepower. Vacuum advance immediately begins to decrease as soon as you accelerate, and at wide-open throttle vacuum disappears. However, it is recommended that you connect your vacuum advance hose to direct manifold vacuum because it will provide you with more vacuum advance at idle, which will help to keep your plugs cleaner. Some motors will idle too fast/rough at manifold vacuum, in which case you will need to connect your vacuum advance to ported vacuum.
Is a HEI rotor phased?
Myth 9: An HEI rotor must be phased. On an HEI, if you use the holes in the housing that were originally there for the vacuum advance, to install your vacuum advance eliminator, there is no cause for rotor phasing. It will already be phased correctly due to the original design. Myth 10: Not necessarily a myth but a fact.
How does a HEI module affect horsepower?
Increased horsepower and torque are a direct result of higher cylinder pressures. However, these higher pressures require more spark voltage and current in order to ensure complete combustion. The beauty of an HEI is that even stock, it applies much more spark energy than a points-type ignition. Generally, stock HEI modules are current-limited to about 4 amps. Better GM performance modules increase this current to around 5.5 amps. Some of the more high-performance aftermarket modules can draw as much as 7.5 to 8 amps of power. The problem with higher amperage is heat. The heat can eventually build up inside the distributor, melt the internal circuits, and destroy the module. This is especially true at idle since the energy remains in the module (since little is needed at idle), which adds to the heat problem.
What is a Hei distributor?
An HEI distributor is still an inductive-discharge ignition, but it exchanges the points for a solid-state electronic switching device called a module. Since this system produces more voltage and amperage output, it demanded a larger-diameter cap to prevent voltage crossfire inside the distributor cap. This larger cap also offered space to position the coil, making the HEI distributor self-contained. All you have to do to run this system is to apply a straight 12 volts to the distributor and you’re ready to run.
How much rpm does a GM distributor give?
Today, there are several aftermarket high- performance modules and coils that can be added to a stock GM HEI distributor to give it excellent spark energy and rpm potential up to 7,000 rpm.
What does more power mean on a coil?
More power applied across the primary circuit of the coil means the coil can apply greater spark energy to the spark plugs. This additional power ensures more complete combustion at both idle and at wide open throttle. Increased horsepower and torque are a direct result of higher cylinder pressures.
How to reduce heat buildup in a module?
The key to reducing heat buildup in the module is to use the special white grease supplied with new modules on the mounting side of the module. This grease creates a better heat transfer path between the module and the distributor body so that the module tends to run cooler. According to ACCEL, you should not use the clear dielectric grease on these modules (like MSD’s Spark Guard) since this is actually an insulator type of grease that will act as a heat transfer barrier, which could lead to trouble.
What happens when a distributor is idle?
The heat can eventually build up inside the distributor, melt the internal circuits, and destroy the module. This is especially true at idle since the energy remains in the module (since little is needed at idle), which adds to the heat problem.
Does an ignition system make horsepower?
Ignition systems don’t make horsepower, but a weak ignition can cost you power if it can’t get the combustion process started. There are plenty of killer ignition systems that could probably weld sheetmetal, but those monster capacitive-discharge (CD) systems aren’t necessary for a typical street engine.
What is the ignition control module?
Many older vehicles use a stand-alone ignition control module. It is responsible for switching the ignition coil (s) on and off to fire the spark plugs. This is crucial, as the engine can’t run properly unless every spark plug is fired at exactly the right time.
What is the purpose of ignition system?
The Ignition System. The ignition system is composed of parts and wirings that work together to create and distribute the voltage power needed by your spark plugs. This process creates the spark that raises the temperature in the air-fuel mixture, making it possible to start combustion.
What causes a misfire in an engine?
You can use them if you’d like to diagnose the problem yourself. Common Misdiagnoses. Other faulty ignition-related components may also cause engine misfires. Spark plugs, spark plug wires, and ignition coils are some of the parts that are usually replaced to fix misfires before testing the ICM.
What does it mean when your check engine light illuminates?
Your check engine light will illuminate once it detects something wrong with your ignition system. Engine Misfires and/or Rough Engine. An engine misfire is usually a symptom of incomplete combustion.
When did GM start using electronic ignition?
GM toyed with electronic ignition systems (using a transistor in a module rather than contact points) as far back as the late 1940s. But ignition systems widely began to evolve. Chrysler first made electronic ignition the standard on all its vehicles in 1972, with a module triggering their oil-filled coil based on input from a wire-wound stator magnet mounted next to a spinning reluctor within the distributor. But the distributor still had a vacuum advance and an internal centrifugal advance for on-the-fly timing changes.
How many wires are in an ignition switch?
It usually contains two separate windings of copper wires. In a traditional ignition system with a single coil, the ignition switch is attached to the positive terminal, where the current from the positive battery terminal is supplied.
Why is timing important in ignition?
Correct ignition timing is crucial because it plays a major role in your engine’s performance and health. The intricacies of your ignition system may vary depending on the specific vehicle you own. On most modern models, the powertrain control module receives input from sensors and controls the operation of your ICM.
What is a HEI distributor?
by Don Bowman. 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. This system consists of a star-shaped wheel on the center shaft, which passes in front of a magnetic pickup.
Where is the coil located on a magnetic pickup?
The coil is an integral part of the distributor and is located in the distributor cap. The control unit for the magnetic pickup is a module located in the distributor. The distributor needs only one wire to supply the module with power. The module sends out a voltage to the magnetic pickup.
Where is the coil located on a distributor?
The coil is an integral part of the distributor and is located in the distributor cap.
Does a magnetic pickup have a vacuum?
The magnetic pickup is not subject to irregularities in firing at high engine speeds, as is the point-type ignition. The HEI also has two methods for advancing the spark. It has a vacuum advance that operates the base plate of the distributor. The distributor is in a semi-retarded position when the engine is starting. Once started, the vacuum produced turns the base plate and increases the advance for the spark.
What causes HEI module failure?
Subsequently, question is, what Causes HEI module failure? Most common cause of module failure is still overheating of the in cap coil, and its layer shorting, causing increased resistance the coil trigger side of the module cannot handle.
What happens if the hot wire from the battery feeds the distributor has no voltage to it?
Engine Fails to Start. If the positive hot wire from the battery that feeds the distributor has no voltage to it, the HEI distributor will not function.
How to test a GM distributor?
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.
How to check if a coil is sparking?
Turn the ignition ON. Touch the probe of the test light to the smaller terminal of the module--it's labeled "G" and had the Green pickup coil wire connected to it. When you pull the probe OFF the terminal, you should hear a snap (the spark) from the coil.
What does it mean when an ECM is in the loop?
When the ECM is "in the loop" it provides extra timing similar to vacuum advance.
Does the ignition module control timing?
There is nothing confusing about my first post.. It answers the primary question; The ignition module does NOT control timing..
What is the role of the ignition module in a vehicle?
on May 26, 2021. The ignition module of your vehicle is the heart of your entire ignition system. Its two main roles are to create a spark strong enough to ignite the air/fuel mixture for combustion and to control the timing of the spark plugs by opening and closing the ignition coil ground circuit.
Where is the ignition module located?
It is usually located on or in the distributor housing in domestic vehicles, and on the firewall or wheel-well in foreign vehicles. Like all automobile components, the ignition module will eventually deteriorate and break.
How to check if ignition control module is good?
If you cannot start the car, you need to test the ignition control module using a light timing tester to check the output of the module. Connect the timer to the positive terminal of the battery and check the continuity of the black output wire while cranking the starter. If the light blinks, the module is good.
How to know if your ignition module is failing?
However, you can anticipate and prepare for the failure. These tips will help you recognize the two most common symptoms of ignition module failure. 1. Overheating. Check out ignition modules on Amazon. Overheating is a common indicator that you could be having an ignition module problem.
What does it mean when your ignition module is overheating?
Overheating is a common indicator that you could be having an ignition module problem. Ignition modules that are overheating will soon completely cease to function and in the meantime can cause cause electrical shorts, engine stuttering, lower gas mileage, power loss, stalling, and gasoline odors in the exhaust.
What to do if your module is overheating?
If you are caught with an overheated module in an emergency situation, you can cool it down with ice water, engine coolant, or refrigerant fluid. However, this is a temporary solution only to be used as a last resort until you can reach repair facilities. 2. Sudden Failure.
