Ive decided Im going to order a IACV off ebay. Will a IACV off a 96-98 vtec car work on my dx?

 

Like Ron said, swap to a vtec ecu and see what codes are brought up. As far as the IACV, I'm not sure on what will exchange with what. I'd assume the IACV's are the same, but I'd wait for confirmation before ordering one. Before you order it, have you tried cleaning yours? If you haven't, I'd suggest trying it just in case your IACV is simply dirty, and not altogether bad. here's a quick run-down on how to clean it.

Also, I'd like to ask a quick question for clarification. When you unplugged your primary O2S, did you let the engine reach operating temperature? If not, then the test wouldn't have shown a change in the operation of the car; until the O2S reaches ~572*F, the car is in open-loop operation and refers to pre-programmed fuel trims; the O2S effectively has no say-so in what goes on until it hits its light-up temp.

 

do you have an open vacuum line some where? Mine had the same symptoms and replaced all sensors to find out that a vacuum line had fallen off.

 

I have no clue where the vacuum lines are, should be, or what they do. The car ran fine for almost 2 years, no work was done to it that would have knocked vacuum lines off, and theres really no way in hell that all these things have gone bad at the same time. Im begining to think theres something wrong with the "new" distributor I bought and instaled on the car.

 

All you have to do to check vacuum leakage is to spray a fine mist of carb cleaner around your engine bay while idling, if you hit a spot that makes the car bog down then you have found a vacuum leak because it sucks the carb cleaner into the motor and stalls a little bit. Hope this helps a bit. My IM vacuum line fell of and there was no way to even see without the trained eye. Thats how I found it... made my tach bounce like crazy too and pulled all of the same codes.

 

hmmm, interesting. Did your car run decent when the engine was cold too?

 

yes actually it did, also it would stammer really bad on take off and balance back out above 40-50 mph too then it was fine... and it would do the same thing taking off the next time... cruise did not work at all either. No one knew what the heck was wrong with my car either it was like that for 6+ months.

 

also you would be surprised on how easy it is to knock a line off accidentally.

 

I checked for vacuum leaks, using my hands and eyes, everything seems to be in its correct spot still. I also tried the original distributor one more time; the car will not start with that one at all. I noticed my negative cable on my battery was all cracked and about to snap, so I bought a new one and replaced it, I also put the original stock pcm back in the car. The check engine light is off, and Im able to drive it for 10 or 15 minutes before it starts acting up and doesnt want to rev or go anymore, idle is at about 100-200 rpms now, and the CEL is off, the car still stammers and sputters and the tach goes to zero usually when that happens, and giving it more throttle has no effect. I'm still stumped here.

 

Well, if the battery was disconnected, it would have cleared all the trouble codes. It could take a little bit of driving before the computer runs the necessary monitors to trigger the CEL.

Also, are you sure it's idling at 1-200rpm? The first thin line on the tach is actually 500rpm, not 0.