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.
What does an HEI module do?
With an electronic module, an HEI can safely operate at much higher current loads. 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.
Is HEI or coil better?
Actually, an HEI draws only 2- to 3-amps, compared to the approximate 6-amps an external oil-filled coil draws. The lower amperage draw results in a much cooler running HEI coil. HEI Coils also run cooler because they are encapsulated in thermal epoxy, which dissipates heat more efficiently than oil-filled coils.
What are the signs of a bad distributor cap?
- Trouble Starting. As the distributor cap gets worse, you are going to have trouble starting the engine. …
- Shaking. If you are experiencing intense vibrations or shaking in your car, it could be due to the distributor cap causing misfires. …
- Stalling. …
- Squealing Noises. …
- Check Engine Light.
What are the symptoms of a bad ignition module?
- Acceleration Issues. The vehicle may shake, vibrate or jerk when the gas pedal is pressed. There may be hesitation or lack of power during increases in speed.
- Temperature Problems. A faulty ignition module can cause a vehicle to overheat. …
- No Power. The engine may turn over without starting.
What are the advantages of an HEI distributor?
The HEI system produces a more powerful spark, which allows for a wider spark plug gap. This delivers better ignition of the fuel/air mixture.
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. … This means that there is no power on the “RUN” circuit when the ignition switch is in the “CRANK” mode.
Are DUI Distributors good?
On the road, light throttle acceleration was smooth and powerful, and the fresh 350 pulled happily toward 5,000 rpm. Since it fits and functions like a GM HEI, the DUI line from Performance Distributors is certainly an excellent alternative that delivers long-lasting performance right out of the box.Is HEI distributor good?
An HEI distributor is a great piece of equipment for an over-the-road car because it is completely self-contained. … But without an external coil, a stock HEI cannot provide a strong spark at rpm levels commonly seen on the racetrack. Engines with higher compression or more horsepower also require a hotter spark.
What problems can a bad distributor cause?In comparison with modern cars and their solid-state ignition systems, the distributor has to be one of the most infernal parts of an older engine. If not regularly checked and maintained, it can cause all kinds of problems, like poor starting, misfiring, low power and, er, being stuck on the side of the road.
Article first time published onWhat can a bad distributor cause?
A bad distributor rotor or cap is one of the common causes of improper combustion. The check engine light will come on if the distributor is not distributing voltage consistently or correctly. A cracked or broken cap and a clogged rotor are one of the major culprits of improper combustion.
What will a bad distributor cap cause?
A faulty distributor cap can cause your engine to stall. Voltage must be produced by the spinning distributor rotor for the engine to keep running. If the rotor does not rotate properly, the engine loses power and stalls out as you’re trying to drive. The longer you let this go on, the worse it will get.
When did GM stop using HEI?
High energy ignition, also known as H.E.I., is an electronic ignition system designed by the Delco-Remy Division of General Motors. It was used on all GM vehicles, at least in the North American market, from 1975 through the mid-1980s.
How many volts does a stock HEI put?
An HEI should have a 10 guage wire run to it. If it’s hooked to stock wiring it may not be getting a full 12 volts. Many cars had ballast resistors or resistor wire running to the stock coil. A GM HEI should run on as low as 9 volts but 12-14.5 is required for good performance.
How many volts does an HEI distributor need?
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 causes an ignition control module to fail?
The number one reason that ignition modules go bad is because of heat. On most of the cars that have a recurring problem with this, they have the original distributor in the car. As the distributor ages and wears, the bushing in the shaft goes goes bad and starts to cause excessive heat.
What problems can a bad ignition switch cause?
A defective ignition switch may cause your vehicle’s interior lights, dashboard lights, and other accessories to turn off momentarily. Intermittent loss of lighting and other accessories is one of the symptoms of a bad ignition switch.
How many wires go to a HEI distributor?
Connect the primary wires to the HEI distributor, via a plug that snaps into the distributor cap. There are two wires in the plug: the hot wire and the tachometer wire. If you are updating from an old distributor, splice the old distributor hot wire to the hot wire of the HEI primary plug.
Do all ignition coils need a ballast resistor?
All cars produced with breaker-points type ignition generally had a resistor of some sort in their ignition system. … And while ignition coil life may be compromised without a resistor, the additional secondary voltage (at the spark plug) is increased which generally improves power.
How does an HEI distributor work?
The HEI distributor is an inductive-discharge-style ignition, but with the points replaced by a solid-state switching device called an electronic ignition-control module. The module works like an electrical switch, turning power on and off to the ignition coil. This, in turn, causes the coil to generate spark.
When did GM introduce HEI?
The HEI system was introduced in late 1974 on some GM cars, and was used across the entire GM product line in 1975. This new ignition had a significantly higher output and longer spark duration, assisting GM meet the ever tightening emission standards.
How does HEI vacuum advance work?
This is how vacuum advance works. At part throttle, high manifold vacuum moves the diaphragm in the vacuum advance canister on the distributor to add more timing. … In the case of the HEI, you can actually purchase an adjustable vacuum advance canister that will allow you to custom-tune the amount of timing advance.
How do you test a HEI distributor?
Use a volt meter to test the hot wire while a buddy cranks the engine over. If the voltage drops below 10.5, check your battery. If the battery is fine, make sure the wire feeding the distributor is sufficient.
What is the difference between HEI and DUI distributors?
The HEI delivers a more powerful ignition spark, and this allows the use of wider spark plug gaps to help ignite fuel quicker, and deliver a more complete combustion. In the world of aftermarket distributors, Davis Unified Ignition (DUI) has been delivering top-of-the-line HEI units for decades.
What is a Davis Unified ignition?
The DUI (Davis Unified Ignition) has everything you need for the ignition in one simple unit. No external coils or spark boxes are needed. Just one 12 volt hot wire hooked up to the DUI sends 50,000 volts of pure spark energy to the plugs for a cleaner, crisper, more powerful running engine!
Where are DUI distributors made?
HIGH PERFORMANCE MANUFACTURING Distributors, D.U.I. (Davis Unified Ignition), is available for Chevy, Ford, AMC, Chrysler/Dodge, Oldsmobile, Pontiac, Buick, Cadillac and Toyota Landcruisers. Based in Memphis, Tennessee, we have always been attracted to the rush of a really powerful ride.
Can a bad distributor cause loss of power?
Bad spark plugs, fouled-up plug wires or a cracked distributor cap can cause spark loss, while compression loss — in which too much of the air-fuel mixture flees a cylinder before going bang — commonly arises from a leaky exhaust valve or a blown head gasket [sources: B&B; O’Reilly].
Can a bad distributor cause backfire?
A bad wire will make the spark’s travel difficult, weaken the spark, or simply push it into an adjacent wire or to ground, resulting in a backfire. The same result can come from a faulty ignition coil, distributor or rotor and cause a more repetitive backfire.
What causes white buildup on distributor cap?
The deposits on your cap indicate that the rotor consistently fires short of the spark plug terminal. This requires the spark to jump the large gap between the rotor and the cap. If the rotor is retarded enough, it might actually bleed voltage off to the previous cylinder.
Can a bad distributor cause no spark?
A faulty engine distributor won’t spark, which will either prevent the engine from starting or cause it a running engine to fail. In order for the ignition system to work properly it is important to keep the engine distributor operating at maximum efficiency.
What happens if your distributor timing is off?
Ignition timing retarding causes the spark plug to fire later in the compression stroke. The effects of retarding ignition timing include reducing engine detonation, which is combustion inside the cylinders after the spark plug fires. This is also known as engine knocking.
