ka24de issue

[Hippieperson]

Me and a friend replaced the geadgasket and timing chain on his ka. Got it all back together and fired it right up, but the timing was off a Lil and it fouled out the plugs. Got it all set right n went to start it back up and it will turn over but not fire up, got new plugs its getting spark and fuel. Started looking around and found this plug undone, not sure where it goes, we've looked for a couple hrs. It comes from the block right under the back of the intake mani, light blue and a gray and white wire. Any info wld be appreciated grately need to get this thing running soon. Thanks.