4000 rpm idle
#23
Cpt. Slow
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Join Date: Oct 2005
Location: Oregon City, OR
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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.
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.
#30
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.
#31
Tweaking Enginerd
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Join Date: Mar 2013
Location: Boulder, CO
Posts: 1,809
Total Cats: 366
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.
This is in the manual.
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skidude
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09-29-2021 03:52 PM