Listen to curly, sounds like your throttle cable may need to be adjusted.

 

I put the old throttle body on and forgot to plug in the air. It idles now. 600 rpm. But not 4000. I find it odd that I had 2 iac units bad. I want to check the voltage at the plug. Does anyone know what I should be looking for?

 

This is one of the most frustrating threads I can remember.

You have a throttle cable. It mechanically opens the throttle valve. This rotates the TPS. I am using the TS TPS reading (2.8%) to guess that the cable may be holding the throttle valve open. I am not saying you need to recalibrate your TPS, although once whatever is holding it at 2.8% is fixed, it should be calibrated in TS. Once you do this calibration, full throttle should always read 99-100%, and no throttle should read less than 1%. If it doesn't, you have a TPS/wiring/throttle body/throttle cable problem, which is why I asked multiple times you check it.

But, I'm glad you fixed it regardless. You should see one pin at the IAC with 12v, the other is the pulsed ground signal from the ECU, which you won't be able to diagnosis with just a multimeter, so don't bother. You can pulse it in test mode with engine off, and if it buzzes, everything is more or less working properly.

 

Sorry Curly. I never did say that almost the whole time the cable had been disconnected. I still need to figure out why it idles so high with the iac connected. I'll check the wiring tomorrow. I have to get ready for work now.

 

I took the plug for the iac off and it idled too low and stalled. I drove it and it ran like crap. Adam, my tuner, should be able to take care of this. I wanted to thank all who guided me through diagnosing. I was frigging clueless.

 

TBF whenever I'm on mobile view it doesn't show the pos or neg cats icons. Which is why I generally never give them out. It isn't a lack of appreciation for anyone who helps me.

 

 

lol at the butt-hurt. Show yourself wussy.

 

It was not me. Not sure why someone is butt hurt. Must have been OP

 

I have thick skin. The last time I was butt hurt was after eating hot peppers. On the other hand, the tuner had the valve mode set to inverted 100% off. When it was changed the idle dropped. He couldn't get close loop to function properly, so at this point I'm using open loop idle. Idle drops with electrical load, like fan or lights. I emailed DIY and I'm going to send a log and tune right now. Tuner thought it was firmware, DIY says its the tune. I'll get it figured out soon hopefully. Because I have to blip the throttle at stop lights, all the Boi racers think we're going for it. I can't wait to have a steady idle. This is frustrating.

 

use test mode, sweep the dutycycle from 0-100, record the settings that result in monotonic-increasing response, if you aren't monotonic and increasing between 35-40-45 but are monotonic decreasing you need to invert the polarity. Be aware that there is a non-monotonic behavior on some ISC/IAC valves from 0-~25% as a fault mitigation (failure of ISC results in a car that still runs).

This is in the manual.