Coil-pack Test


Many miss-fire problems with the RB26 motor can be attributed to the ignition system, as part of the procedure for determining a miss-fire cause, it's a good idea to inspect the coil packs. If you don't know how to get the coils out of the engine, follow my guide for Compression Testing up to the point where you have the coils out. From there you need a multi-meter, you're hoping to see a resistance between 0.6 and 0.9 Ohms, anything outside this range means the coil-pack is finished and is likely causing spark issues.

From Nissan Service manual page EN-248


3 comments :

  1. There is more to it than just this test. I rarely find a bad coil, its mostly other things that cause a mis-fire.

    The harness to the coils, is often crispy, and causes issues. Also the boots on the bottom of the coil, you can sometimes see spark leaks though the boots.

    Check inside the boots for the carbon/spring. They occasionally fall out.

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  2. all very good points too! thanks for reminding me!

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  3. something else to look out for:
    marks on the coil pack from where arcing has occurred. its usually on the underside of the pack, above the boot but under the mounting bracket.. looks kinda like bubbles. usually small patches around 5mm wide.

    if arcing is occurring, you'll know it by the sound usually. lift the bonnet and stick your head under. if you hear a click directly followed by a misfire then this is the issue. for further validation, stick the car in the garage and turn off all the lights (or wait until night time if you dont have a garage) and you'll see blue lighting from under the packs.

    dont bother getting second hand coil packs from a wrecker. always gets new.

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