Skipping

Conductive spark plug spring hung up in the boot shoulder? Properly torqued with clean wells? Using a recommended plug by the spark plug manufacturer? Assume all the plugs have gaskets.

Gaping is not just bending the ground electrode at some weird angle, ground electrode has to be perpendicular to the vertical axis, and the two platinum blocks aligned, mine are gaped at 25 mils. Aligning all four boots centered of the plugs can be done at an angle so you can see what you are doing. Prefer the words, hesitation or a misfire for improperly gaped and installed plug.

Maybe the only guy on this board that knows how to properly gap and install plugs, used double platinum and my 1.4L loves them, perfectly hesitation free, takes off like a rocket with that turbo and get excellent fuel economy.

Engine must start the instant I hit the start key regardless of ambient temperature, -30*F to 110*F. Any hesitation or misfire is unacceptable. Raw gas is going to the catalytic converter, and the O2 sensor thinking the engine is running lean enriches the other three cylinders, drastically shortening the life of the cat with more expensive problems.

This is what I went by.

Autolite - Online Parts Lookup

[url]http://parts-catalog.acdelco.com/catalog/catalog_search.php

https://www.ngk.com/Automotive-NGK-l1411.aspx

https://www.boschautoparts.com/en/auto/spark-plugs

http://www.championautoparts.com/Find-My-Part.html

https://www.sparkplugs.com/Automotive-l134.aspx
[/URL]

Always forget to mention this because I do this without thinking. Practically all the plugs are of the resistor, carbon resistor is embedded in the upper part of the ceramic.

With an ohmmeter check the resistance between the top connector and center electrode, should be 8,000 ohms, if much more, or can even have an open circuit, part of the spark would occur in that resistor connection, and not across the electrodes where it belongs. Just as important as getting the proper gap.

Another test requires a spark plug tester, sealed area where you can increase the pressure to 150 psi, may be find you have blowby between that ceramic and metal base. Is nice to have this basic equipment, your engine is the last thing you want to use to even test brand new plugs.

Was really unhappy when I drove my brand new Cruze home, very particular, was having misfires. Gaps were way off, springs were hung up in the boot shoulder.

Debate on whether to put a very thin coating on the threads, its your vehicle, wreck if you want, been doing this before most of you were even thought of. Even with some plugs where the threads stuck out into the combustion chamber, put those in my lathe can removed those worthless threads. Also dielectric grease in the boots, even with the spark plug wire type, if you don't they will bake on.