Mechanics

Ignition Timing Adjust

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Step by step automotive guide on how to adjust or set ignition timing, this article pertains to distributor style of ignition systems only which are featured on older engines.

Difficulty Scale: 2 of 10

Begin with the engine "OFF", vehicle on level ground, in park and the emergency brake applied.

Step 1 - A timing light is used to detect the initial electrical charge to the spark plug wire of the number 1 cylinder, (forward most cylinder of the engine.) through the use of a clamp on lead. The remaining leads are attached to the positive and negative side of the battery.

Step 2 - Next, locate the crankshaft timing marks, most engines timing marks are at the front of the engine on the harmonic balancer. Near the balancer there is a small pointer or scale to align the balancer mark.

Step 3 - Once the light is connected, start the engine and run until warmed to operating temperature, the timing light will strobe and illuminate the balancer mark as the engine runs. This gauge or pointer should align with the mark on the balancer.

Step 4 - To adjust the timing, loosen the distributor and turn slightly one way or the other to achieve the desired setting which is located on the under hood emissions sticker or owners/repair manual. Once an adjustment has been made re-tighten the distributor hold down bolt or bolts. Also some vehicles have an PIP (profile ignition pickup) that needs to be disconnected before adjustments can be made, this should be mentioned also in the under hood sticker.

Helpful Information

Engine timing must be set to a specific degree in relationship to the crankshaft. If this timing becomes misaligned it can cause low power, poor gas mileage, engine detonation (pinging) and backfiring. On straight 4 and 6 cylinders the number one cylinder is pretty obvious, but on "V" style of engines like the V8 its a little more tricky. The cylinder heads on every "V" style of engine are offset (one is further forward.) The most forward cylinder head is the side of the engine where the number one cylinder is located.

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AUTHOR


Written by
Co-Founder and CEO of 2CarPros.com
35 years in the automotive repair field, ASE Master Technician, Advanced Electrical and Mechanical Theory.


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Article first published (Updated 2014-07-10)