Distributorless Ignition System – No More Moving Parts To Wear Out

Distributorless Ignition System - No More Moving Parts To Wear Out
Distributorless Ignition System - No More Moving Parts To Wear Out

The distributorless ignition system, is a completely solid state electronic system, with no moving parts.

So, with no distributor, there is also, no distributor cap or rotor to replace. And, no troublesome vacuum or mechanical advance mechanisms, to cause timing problems.

Because, the distributorless ignition system; uses an electronic control unit, an ignition module and multiple ignition coils.

The components of distributorless ignition system are:

  • Ignition Coils
  • Spark Plug
  • Ignition Control Module (ICM) or Ignition Control Unit
  • Ignition Switch
  • Battery
  • Crankshaft Triggering Device
  • Camshaft Triggering Device
Distributor Ignition System
Distributor Ignition System

How Does It Work

So, when we turn on the ignition switch, the current from battery; starts to flow through the ignition switch, to the (ECU) of the vehicle. Then, the (ECU) processes data, from sensors and calculates the ignition timing.

Triggering wheels mounted on the camshaft and crankshaft; identify the position of crankshaft and camshaft. The position sensors, are equipped with a magnetic coil, which generates a magnetic field. So, when the gap of a triggering wheel, comes in front of the position sensor; a fluctuation in the signal would occur. These signals then stop or start, the flow of current, to the primary winding of the coil.

Over time, the evolution of ignition systems, has provided a number of benefits. But, that does not mean, they are trouble free. Failures can and do occur, for a variety of reasons.

But, knowing how to identify and diagnose; common ignition system problems, can save you a lot of guesswork. This will help the next time your engine cranks; but refuses to start or one that runs, but is missing.

If an engine cranks, but will not start, is it fuel, ignition or compression? So, ignition, is usually the easiest of the three to check. Because, on most engines, all you have to do is, pull off a plug wire and check for spark; when the engine is cranked. But, on the coil-over-plug (COP) system, there are no spark plug wires. As a result, you have to remove a coil and use; a plug wire or adapter to check for a spark.

Testing The Distributorless Ignition System

So, if there is no spark in one cylinder, try another. No spark in any cylinder, would most likely indicate; a failed module or crankshaft position (CKP) sensor. Many engines with electronic fuel injection; also use the crankshaft position sensor signal, to trigger the injectors. So, if there is no spark and no injector activity; the problem is likely in the crank position sensor. No spark in one or two cylinders, that share a coil; would tell you a coil has probably failed.

(COP) Distributorless Ignition System
(COP) Distributorless Ignition System

The coils in a distributorless ignition system, function the same as those, in ordinary ignition systems. So, testing is essentially the same. But, the driveability symptoms, caused by a weak or dead coil; will be limited to one or two cylinders, rather than all the cylinders.

A Low (MAP) sensor output voltage, or a coolant sensor that always reads cold; will allow more spark advance than normal. This, in turn, may cause detonation (spark knock) problems; when the engine is under load. Also, a faulty knock sensor (KS) or an (EGR) valve that is not working.

In contrast, a High (MAP) output voltage, or a misadjusted throttle position sensor; can have the opposite effect. This would cause the spark control system, to retard timing more than normal. Retarded timing, will reduce performance and fuel economy.


Do not forget, that ordinary secondary ignition problems; can also cause misfires, the same as a conventional ignition system. Also, a bad spark plug wire or a fouled spark plug; will act just like a weak or bad coil.

The distributorless Ignition System, has several advantages over conventional distributor type systems.

  • Less voltage loss, from the coil to the plug.
  • With fewer connections and the elimination of the distributor rotor to cap air gap.

So, the evolution of ignition systems, has provided a number of benefits. As a result, drivers with newer systems enjoy better fuel efficiency; more reliable operation and reduced maintenance costs.

Thank You !