Hi guys, i recently swap motor, same d16 coming from another civic i stripped last year, that motor worked great, but while installing it, it was sitting at a feet from the ciment and drop down from the throttle's side, well my mistake, anyway i installed it and when i started it, works like a charm, but after 2-3 min, when the choke trying to shut, the idle starts to go up and down constantly, doesnt matter when i drive it tho, did i broke something? it hit pretty hard on the ciment :/ only thing ive noticed is the air pipe for the brake hose that bent just a lil but not enough to me i think

 

I have had the same problem for going on three years now. And didn't drop my engine. Mine started after engine build and turbocharging/tuning. I have just learned to live with it. Sorry I don't have any info on fix.

 

It must be a sensor or a leak for sure! Im planning to take the ol throttle out and install the one from my old d16, might fix the problem. Hope its not a computer problem tho, can it be? it was automatic and i swapped everything to standart, complete car wires, computer, motor, everything! noticed the computer of the standart was all rusted at the bottom left corner... That computer leaves me doubts, i know im suppose to get a check engine code, because i have headers and the second sensor is not behind the catalic, so its gave me a check engine light, but since i swap everything, no check engine, i wonder if you can use the automatic computer with standart

 

I was told it has to do with the idle air control duty cycle, mine is at a set duty cycle because of the tuning software. Have you tried cleaning your IAC or fast idle thermal valve?