Did a recent headoverhaul on a 95 pick up 22re 2wd. It turns over but wont start and no check engine light. I got spark, fuel, compression, but wont start. Vacuum hoses are done correctly and so are plugs. Except for one plug which I see nothing it connects to. Very small round grey one that is along the part of the wire that contains the one going to the throttle body. Any ideas or tips on what to look for?