Throttle Open 20% with Key Off

[rgpmalibu]

Hello, I have a 2004 LM7 in a '78 Chevy Malibu. Just did a cam swap and I'm beginning the tuning process. The car started, idled, and drove normally when I did a couple of tuning drives. On about the fourth drive (I was paying attention to other stuff)I noticed that my throttle was open to about 19% when my foot was off the gas. On the first startup, there weren't any red flags like super high idle, so I didn't catch it. When I did finally catch it, I thought it was a relearn process, so I did that, and it didn't do anything. Checked it with the car off and it still read about 19.8% Then I turned on the scanner, took the intake off, and pushed on the throttle blade with my finger and it actually closed. And the TPS reading went to 0.1%. What would cause the throttle blade to be open to 20% when the car isn't running? I looked at the pedal and it seems to be free and correct. Ask me questions and I'll answer them if I can. Pretty new at this...
Here's my current tune (in progress for VE/SD tuning) and the log of me pushing on the blade.
Thanks for taking a look, I appreciate it.

[SiriusC1024]

That's typical for ETC GM vehicles.

[rgpmalibu]

Is the throttle body failing? Should I replace it? I'm not getting a voltage signal from it either, but it seems to be otherwise operating normally.

[blindsquirrel]

Throttle Body Assembly

The throttle body assembly consists of the throttle body, the throttle position (TP) sensors, and the throttle actuator motor. The throttle body functions similar to a conventional throttle body with the following exceptions:
- An electric motor opens and closes the throttle valve.
- The throttle blade is spring loaded in both directions and the default position is slightly open.
- There are 2 individual TP sensors within the throttle body assembly.

[blindsquirrel]

The PID for 'Throttle Position Sensor [volts]' does not exist for DBW, it has two sensors, TP1 and TP2. Only the cable TBs have a single sensor (TPS).

[rgpmalibu]

The log shows "slightly open" as around 19%. That seems a little more than slightly. It seems like I should be looking for a ratio closer to zero, unless there is a reason that it's open that far. I'm not so much concerned with the voltage as the initial position itself. In anyone's opinion, is this a sign of failure? It seems odd that the blade WILL close all the way, but mine just doesn't. Should I be ignoring this ratio and just let the computer rely on manifold pressure? Or should I be looking at a replacement. Just looking for some clarity on this. Many thanks.

[SiriusC1024]

The log shows "slightly open" as around 19%. That seems a little more than slightly. It seems like I should be looking for a ratio closer to zero, unless there is a reason that it's open that far. I'm not so much concerned with the voltage as the initial position itself. In anyone's opinion, is this a sign of failure? It seems odd that the blade WILL close all the way, but mine just doesn't. Should I be ignoring this ratio and just let the computer rely on manifold pressure? Or should I be looking at a replacement. Just looking for some clarity on this. Many thanks.

That's typical for ETC GM vehicles.

[rgpmalibu]

Sorry, I have a tendency to look for problems where there might not be one. Thanks.

[blindsquirrel]

https://www.rockauto.com/en/catalog/...ttle+body,6472

Look at the photos, some of them show the 'at rest' blade position pretty well. That's just how they are. That's the 'neutral' position where they sit with no power.

[rgpmalibu]

I see that now, thanks. I never noticed that before, even when I cleaned it. It took looking at the scan to pick up on it.