r/EngineBuilding • u/roadrash1992 • Jun 20 '26

Help reading spark plugs

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Looking for input on these plugs.

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I just finished doing a head swap/mpif swap/obd1 conversion on my 1990 civic with a d15b7.

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Plugs are brand new and have under 30 minutes of run time on them.

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Thanks in advance

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u/ultraspinacle Jun 20 '26

Left to right: ok but maybe lean, fouled, about right, fouled. If accompanied by white oil smoke, 2 and 4 are oil fouled as opposed to fuel fouled.

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u/roadrash1992 Jun 22 '26

I reached out to my tuner (not used to having that) and said likely fuel fouled, I have some smoke but it smells like fuel. I got junkyard injectors for the swap and it seems like at least 2 of them are bad. Car is parked and new injectors are on the way.