I need some help brainstorming....my crx has an ls vtec in it. The car has been converted to OBD1. Once it warms up it has a flucuation in idle up and down.....now only when it is warm. This usually means IACV. I bought a brand new one (after trying a couple I had laying around) from honda and installed it but it still does it. I burped the air out, with my radiator funnel until the thermostat opened. If I cover the upper hole in the throttle body it idles smooth, which again points to the iacv. No check engine light. Kinda weird. Any thoughts?

 

my crx did that after it sat for a while. turned out to be a bad vacuum hose on the intake. i did take apart my IACV before i did that too, and had the same result.

 

you know my crx has been sitting (started every once in a while) in the driveway. I didnt notice any vaccum leak but thats a good thought i will check that. Did your (that had the vaccum issue) only do it when it was warmed up too?

 

Have you had the battery disconnected? I remember when I drained my battery it took a while for the computer to re program itself.

 

Get some carb cleaner (or some other combustible) to check for vacuum leaks. Spray around the intake manifold and listen for the motor to rev up a little. Helps when tracking down a small leak.

 

yea i am going to try this when I get home, but if I had a vacuum leak i would think the idle issue would be all the time, this only happens when the car warms up. no?

 

not recently, but it was dead at one point and i charged it, it has been holding without any issues.

 

still no luck, checked for vacuum leaks and all seems good, put another brand new iacv on and still have the issue. And again if i cover the top hole in the throttle body it smooths right out. Any other thought?

 

no one? No vaccum leaks, and brand new iacv.

 

got a new ecu and seemed to fix the issue. I bought a computer from pherable.net, love the customer service and the map in the ecu. Car runs great. I took out the chip and read it in to my moates usb chip reader and saved the map to my pc. Now the map has the options "idle target" set for 750, but the car idles at around 11 or 12 hundred. Should I be worried?