To check the coil secondary resistance, connect an ohmmeter between the rotor button and the BAT terminal. Then connect the ohmmeter between the ground terminal and the rotor button. The resistance in both cases should be between 6000 and 30,000 ohms. Replace the coil only if the readings in Step 1 and 2 are infinite.
How do I know if I have a bad HEI coil?
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.
Can you test a coil with a multimeter?
Connect your multimeter to the positive terminal or pin of your coil, and to the high output terminal that goes to the spark plug. Most ignition coils should have a secondary resistance falling somewhere between 6,000 to 10,000 ohms;however, refer to manufacturer specifications for the correct range. Aug 1, 2016
How do you bench test a HEI distributor?
Put the HEI in a vise, (don't clamp it down real tight) Hook 12v to the BAT terminal, and ground the vise. When you turn the gear it'll spark. If it does not, look at the rotor and then the module and pickup coil. If you have a Weller style soldering gun you can test the module and coil with that. Mar 7, 2008
How do you test a GM ignition coil?
Place a lead from the ohmmeter on either side terminal and one in the center high tension terminal. Read the ohms off the meter. You are looking for 7500 to 10,500 ohms, and if the reading falls outside that range, it indicates a defective coil.
How do you test a HEI control module?
How do I test my HEI module? 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. Jan 25, 2020
What are signs of a bad distributor?
Usually a faulty distributor rotor and cap will produce a few symptoms that alert the driver that service may be required. Engine misfires. Engine misfires can occur for a number of reasons. ... Car doesn't start. ... Check Engine Light comes on. ... Excessive or unusual engine noises. Jan 7, 2016
How many volts should my coil have?
12 volts The voltage reaching the coil may be 12 volts , or about 7 volts if the coil has a ballast resistor . Most electrical equipment works on 12 volts, but most modern cars have a resistor in the ignition system to assist starting. The coil in a ballast-resistor system is rated at 7-8 volts instead of 12 volts.
How do you test a 12v ignition coil?
To check a 12 volt coil, set the multimeter to at least a 200 Ohms setting. Attach both leads of the meter to the coil-terminals with black to the negative terminal and red to the positive one. The normal, acceptable range for a standard 12-volt car is 1.5 to 1.7 Ohms. See if the reading is within this range.
What happens when an ignition coil goes bad?
As the ignition coils are among the ignition system's most vital components, an issue can cause spark to be compromised, which can quickly lead to performance issues. Faulty coils may cause the vehicle to experience misfires, a rough idle, a loss in power and acceleration, and a reduction in gas mileage. Jan 8, 2016
How do you test a HEI distributor?
To test the resistance of the coil, remove the coil cover so you can see the red and yellow wire. Using the multi-meter set on the ohms setting, touch the positive lead to the red wire terminal and the negative lead to the yellow wire terminal. Testing the secondary circuit of the coil. Dec 11, 2017
How do you test a GM distributor module?
How to Check the GM Ignition Control Module Open the hood of the GM vehicle. Locate the ignition module. The ignition module is found directly next to the cylinder coil packs. ... Connect the positive test light lead to the ignition module signal wire. You will notice a wire harness on the side of the module; the signal wire is the middle wire of the three.
What would cause a coil not to fire?
There are a few reasons for no spark, new coil pack could be defective, crank sensor, ignition module or bad wire in primary circuit, faulty ECM/PCM. You may have to have a good technician have a look, diagnose and estimate repair. ... Most likely the crank or cam sensor. Sep 20, 2016
What are the signs of a bad ignition control module?
1. Engine performance issues. One of the first symptoms of a problem with the ignition module are engine performance issues. If the ignition module fails or has any problems it can lead to performance issues with the vehicle, such as misfires, hesitation, loss of power, and even reduced fuel economy. Jan 7, 2016
How do you test an old ignition coil?
Connect your multimeter to the positive terminal or pin of your coil, and to the high output terminal that goes to the spark plug. Most ignition coils should have a secondary resistance falling somewhere between 6,000 to 10,000 ohms; however, refer to manufacturer specifications for the correct range. Aug 1, 2016
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. Sep 28, 2013
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 check for a bad distributor?
Check the Arc Put the metal part of a screwdriver against the metal of the plug wire. Place the metal screwdriver near the electrode of the distributor. It should not touch the electrode. Step away from the hood and have someone watch the arc while the ignition is turned on.
What problems can a bad distributor cause?
Since the engine needs that spark to run, a bad distributor can result your car stalling when it idles. 4. Your engine is misfiring: If the distributor isn't providing enough juice to the spark plugs, it can cause your engine to misfire, which typically feels like the engine is stumbling. Jun 21, 2018
Will a bad distributor throw a code?
Re: can your distributor fail and not throw a code? The coil and igniter can go bad and not throw codes. If either goes bad you will get no spark, and thus no start.
How do you test a distributor coil?
The only safe way to test for spark is to use a spark plug tester tool. If a coil problem is suspected, measure the coil's primary and secondary resistance with an ohmmeter. If either is out of specifications, the coil needs to be replaced. A coil can be easily bench tested with a digital 10 megaohm impedance ohmmeter.
Should negative side of coil have power?
The power from the ignition switch need to go to the plus side of the coil and the negative goes the the distributor on a 12v system. That should be opposite what it was on a 6v positive ground. Other then that start checking connections down the line from the ignition switch for power. Nov 24, 2012
What is the difference between a 6 volt coil and a 12 volt coil?
6 volts systems use a coil with around 1.5 ohms between the two primary terminals. 12 volt systems have 3-5 ohms total,similar 1.5 ohm coil with a ballast resistor adding another 1.5 ohms. Or some 12 volt coils have 3-4 ohms built into them. Apr 20, 2009
Does an ignition coil need to be earthed?
The coil does not need an electrical ground, but it does need a thermal ground for heat dissipation, meaning that the "ground" could be compromised by paint etc. and still serve its purpose as a thermal point of dissipation. May 26, 2014
How do I know if my ignition coil has power?
Locate the positive or power wire attached to the engine coil. Check for power using a test light. If this wire has no power, then your ignition coil is not receiving current. You should check the wiring from your ignition switch to the coil for breaks in the wire and repair them. Oct 31, 2019
Do you need a resistor with a 12 volt coil?
If a 6 volt ignition system is converted to 12 volts and a Delco style 12 volt coil with an internal resistor is installed as part of the conversion, no external resistors are required. The 12 volt battery must be connected so the negative (-) battery terminal is connected to ground. May 14, 2020
What happens if ignition coil is wired backwards?
To answer the original question, yes it will work if connected backwards but it will not work correctly. The design is for the current to flow in 1 direction and for the circuit break to be on the negative side of the coil. If wired backwards in a points type ignition it will almost act like a flaky condenser. Mar 21, 2009
What does a bad ignition coil sound like?
Engine misfiring will be seen in a vehicle whose ignition coils have failed. Trying to start the engine of such a vehicle will result in engine misfiring that sounds like a coughing, sputtering noise. When driving at high speeds, jerking and spitting will be seen in the behavior of the vehicle.
How often do ignition coils fail?
The ignition coil on your car is supposed to last around 100,000 miles or more. There are a number of factors that can lead to this part become damaged prematurely. Jan 14, 2016
Do HEI distributors need a coil?
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. ... 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.
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 check voltage on a distributor?
Unplug high tension wire from coil that goes to distributor and insert a short spark plug wire. 3. Turn the ignition on and check with test light or volt meter at the battery side of the coil to make sure you have proper voltage there. Apr 22, 2012
How do you test a distributor module?
Check for voltage at the coil positive terminal when the ignition key is on. Place the red lead of the multimeter on the positive coil terminal. Place the black lead to the battery negative terminal. Turn on the ignition switch to the ""Run"" position.
Where is the ignition control module located?
Where is the ignition module located? The location of the ignition module depends on where the vehicle was manufactured. In a domestic model, the module sits on, inside, or near the distributor housing. Foreign models will hide their ignitor within the vehicle's firewall or wheel-well.
Can a bad ground cause no spark?
Bad grounds can cause no spark issues though. It can cause the ground to ground through the ecu frying it. If you get a single spark when turning on the ignition then nothing when cranking it's the ecu. It's a really good idea to go over all your grounds on a regular basis anyway. Dec 16, 2015
Is there a fuse for ignition coil?
The ignition relay is one of the most important electronic relays found on modern vehicles. It is usually located in the fuse and relay panel beneath the hood, and is responsible for providing power to the vehicle's ignition system, and some of the fuel system's components. Jan 11, 2016
What happens when one spark plug is not firing?
Failing spark plugs can cause the car engine to misfire and thus affect its performance. A single spark plug that fails to ignite the fuel-air mixture can cause a halt in the running of the engine. It can result in incomplete combustion and damage to the catalytic converter of the car.
How do you check voltage on an ignition coil?
Use the multimeter to check the removed ignition coil. Connect an ohmmeter directly to the component connector PIN 1 and PIN 2 in order to measure the primary winding. high-voltage outputs of the ignition coil.
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. May 31, 2007
Can a bad distributor cause loss of power?
The most common cause for a misfire is a problem related to the ignition system. Misfiring can be caused by loss of spark; imbalanced air/fuel mixture; or loss of compression. ... This includes worn, fouled or damaged spark plugs, bad plug wires or a cracked distributor cap. Sep 21, 2016
How do you test an MSD distributor?
Magnetic Pickup in the Distributor The magnetic pickup in MSD Distributors can also be checked with an Ohm meter to make sure it is within operating specifications. Once again, connect the Ohm meter's leads to the two terminals of the pickup. The resistance should be within 400 - 1,300 ohms.
How do you tell if you have points or electronic ignition?
If you do have a standard distributor cap, you can open the cap up and peek inside. A points type ignition will have what are called points (duh) installed in the distributor, just below the rotor (that colored plastic part that spins around when the engine is running). Mar 6, 2017
Will a car run with a bad distributor?
No. Generally, if you have a bad distributor in your car, the engine will fail to start. Oct 13, 2020
How do you adjust the timing on a distributor?
To adjust your timing, all you need to do is turn the distributor housing one direction or the other, depending on whether or not you want to advance or move back the timing. If the rotor turns clockwise, you'll advance the timing by rotating the distributor counterclockwise, and vice versa.
What happens if you put the distributor in wrong?
Re: Installed Distributor Wrong?? It won't do anything unless the spark has a path to ground. The way you have it, an open, the spark may be there but with no place to go. You need to put a plug in the wire even if you then lay the plug on the intake for the ground. Feb 8, 2005
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