raene

To make a long story short, I readjusted my valves (checking clearances between the lifters and the camshaft lobes this time instead of between the lifters and the valves) and it idled jest fine!

The downside to this is after blipping the throttle while it was still cold (this is the test to see if it's running right; it always would stall if I did these prior to adjusting the valves...) the idle went down to about 500 rpm and stayed there. I took it out for a testdrive; after it warmed up fully the idle stayed pegged at 750, though very rarely it would go down to 600 or so, then climb back to 750. No wandering was evident during the entire time, just that worrying low idle... Yay... :does happy dance:. Obviously something's still wrong, but it's a lot better than before!

The O2 sensors remain unplugged. During my driving I could tell the ECU was playing with the air/fuel mixture, leaning it out. Eventually the car started doing the part-throttle hesitation thing again, REALLY bad this time, to the point where I practically had to floor it to keep it moving... Drove for about 2 minutes longer, and then someone tried to tailgate me, then move around me to do a flyby. Of course I downshifted and seriously embarassed his *** (I never even got to see what kind of car it was, he wouldn't pull even with me after I slowed to about 40km/h) and my CEL came on, showing Code 1 (primary O2 sensor). The hesitation problem simultaneously disappeared.

Summing up...

I'm thinking that perhaps this is a problem with accidentally reversing the wires between the primary and 2ndary O2 sensors. As I can tell, the primary sensor is reading rich and the ECU correspondingly leans the mixture in the cylinders it senses as running rich. If the sensors are flipped, then it'll lean out cyls #3 and #4 instead of #1 and #2, causing one to run extremely rich and the other to run extremely lean.

That's my theory, anyway... any thoughts?? elusiveracing23, Hondata, where are you guys?

raene

No sol'ns to the idle problem yet, but I unplugged the O2 sensors directly from the wiring harness and reconnected the O2 sensors in the engine bay, so now I can still view what's going on with the Autometer A/F gauge.

Long and short of it is, part throttle is STILL resulting in a lean-running condition! The only difference is, for some reason it's not leaning out enough to cause detonation, and it seems like the part-throttle condition with unplugged O2 sensors causes both pairs of cylinders to go lean instead of just #3 and #4 (like it did when the O2 sensors were plugged in). Hoo boy .