Trouble Shooting
Now that you have the best ignition available for your Classic car you will no doubt want the experience to be the best. So why not make the ignition system the best it can be by adding new plugs, wires and a coil of not less than 1 Ohm.
My old distributor works but the 123 does not.
1.) Disconnect the original wiring from the coil +ve and -ve. Both the tachometer wire and the distributor feed wire. Leave the 123ignition connected to the coil as directed. Now run a jumper wire directly from the fuse box picking a 12v non-keyed power supply and connecting it to the positive side of the coil. Note: if it starts you will need to disconnect the jumper wire from the source to turn it off.
This will take the 123ignition out of the ignition circuit in the car. If there is too much resistance in the original primary circuit it will cause the symptom you are experiencing.
2.) On some Mercedes there is a brown ground wire that goes from the coil negative to ground. This wire will need to be disconnected.
3.) If your static time is too far out. It will not fire. Try advancing or retarding the timing by physically rotating the distributor until it fires.
4.) A lot of problems are caused by a bad primary ignition circuit, specially high rpm problems. This means the circuit: Battery (+) --> Contact switch --> Coil (+) --> Coil (-) --> Ignition (black wire) --> Ignition to ground (minus (-) of the battery must all be in top shape.
This total circuit has a very low resistance. For example 3 Ohm when you use a Bosch blue coil or 1,8 Ohm with a Bosch red coil.
You will get a weak spark when there is a bad connection (resistance) somewhere in this circuit (for example a bad contact switch or a bad connection between the ignition and the battery (-).
5.) Never trust old coils as they may have been subjected to overheating which would damage the coil.
6.) Most cars are well along in years and have had multiple owners. Often what you see in the wiring is not always correct. Make sure the correct wires are going to the +ve and -ve side of the coil. While the car may run with the old points if the wires have been crossed it can keep the 123ignition from functioning properly.
7.) Take the red wire off the coil positive and connect it to the switched side of the fuse block. This also solved a tachometer issue on a customers car.
8.) Weak Spark, Use a good quality spark plug wire if you have a weak spark. Check all connections in the ignition circuit for bad connections. I would check the voltage of the coil under load. We cannot over emphasize the need to have good connections everywhere. Also check the GRND and try another coil.
9.) Re check your wiring. On TUNE models the Blue wire (curve 1) goes to a good ground. The yellow wire goes to a power source (6 or 12v) and when it is energized provides curve 2.
10.) To check if the 123 works in the car, keep the coil connected to the 123. Connect the coil high tension directly to a spark plug. Make sure the plug is grounded. Crank the motor and look for a spark. Note that this test will only work if the spark plug and the coil are in good shape.
MGB Related Issues with Smith's RVI Tachometers
If you have found some helpful hints for unforeseen installation issues, please share them with me so I can post them here.
Thanks
Ed
The following checklist is from the mfg.
Are you experiencing issues with your 123ignition?
Here’s a checklist to thoroughly verify common setup issues.
Troubleshooting Guide
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Improperly Mounted Rotor Arm: Ensure the rotor arm is securely pressed onto the magnetic disc.
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Damaged Carbon Pin in the Distributor Cap: Inside the distributor cap, there’s a carbon pin with a spring that makes contact with the rotor. Verify that this pin is intact and properly connects to the rotor.
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Cable Damage or Breakage: Check for any exposed copper core in the cables that may contact metal or liquids, as this can cause performance issues.
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Incorrectly Mounted Distributor Cap: The distributor cap only fits one way on the 123 housing. Double-check that it’s correctly aligned.
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Corroded Connections in the Distributor Cap: Examine the terminals inside the distributor cap where the spark plug wires connect. Make sure these connections are clean and free from rust or corrosion.
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Incorrect Wiring of the 123ignition (Check the Wiring Diagram): The 123ignition unit has at least two wires, but models may have up to six. Carefully follow the wiring diagram, available on our website, to ensure proper connection. Note that a negatively grounded 123ignition (with two wires) will not work in a positively grounded vehicle.
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Loose or Faulty Connectors: Verify that all connectors, such as those to the ignition coil, are making solid contact. Pinched connectors can prevent the wire from making good contact, and vibrations in the vehicle may cause further disconnections, leading to misfires.
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Faulty Alternator, Battery, or Voltage Regulator: An unstable voltage supply can cause spikes, affecting ignition performance. The 123ignition includes protection against voltage surges, but stable on-board voltage is essential. Faulty components, like the alternator, battery, or voltage regulator, may destabilize this voltage. Avoid using a jump starter, as this can damage the 123ignition. As a test, try driving with the headlights on—if misfires decrease, voltage spikes might be the cause.
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Good Grounding Connection with the 123 Housing: For 123ignition models with just a red and black wire, the 123 housing itself functions as the ground (negative). Ensure it has a reliable connection to the engine block. If unsure, add an extra ground wire using one of the screw holes on the 123 housing.
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Check Spark Plugs and Leads (We Recommend Silicone/Carbon HT Leads): Regularly inspect your spark plugs and ignition cables for correct function and connection.
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Incorrect Timing Adjustment of the 123ignition: To ensure optimal performance, precise timing adjustment is crucial. Our website’s support section includes a video tutorial for setting timing on a Peugeot 404. If you’re uncertain about the timing, consider adjusting it with a timing light at idle.
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Defective Ignition Coil—Consider Replacement: Old or faulty ignition coils may cause internal sparking. We recommend purchasing a new ignition coil with your 123ignition for best results. Use the correct coil for your engine:
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2-cylinder engine: recommended primary resistance of 3 Ohms (minimum 1 Ohms).
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4-cylinder engine: recommended primary resistance of 3 Ohms (minimum 1 Ohms).
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6-cylinder engine: recommended primary resistance of 1.8 Ohms (minimum 1 Ohms).
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8-cylinder engine: recommended primary resistance of 0.8 to 1 Ohm.
The 123ignition is incompatible with ballast resistors on ignition coils, so be sure to remove any ballast resistor.