[Gmecm] Idle Speed

[jryan at caminofx.org]

I have a new GM long-block 350 with a throttle body from a Camaro and  
an Edelbrock 3704 intake manifold.  The ECM is a 1228746, and I am  
using an ANLU PROM from an '89 9C1 Caprice.

All in all, the combination runs well, but I am curious about something.

I went through the minimum idle speed procedure when the weather was  
relatively cold (in the 40s F daytime).  I got it to idle slow but  
smooth, around the speed set in the ECM constants table in the PROM,  
about 560 RPM or so.

Lately, the weather has warmed up some (to the mid-70s F daytime), and  
the engine seems to idle faster.  It was idling at around 800 RPM when  
I shut off the engine after getting home from work yesterday, and when  
I parked at work this morning.

Watching the temperature gauge in the dashboard, it seems like, to a  
point, it idles faster as the engine temperature increases.  I don't  
see any values in the PROM that would do this, but I may have  
overlooked something.  Is this normal, or should I look for something  
wrong?

For what it's worth, the Camaro throttle body does not have an  
adjustable TPS.  It just screws on.  You can't move it.

On Saturday, I hooked up my laptop with WinALDL while it was idling  
relatively fast, and it showed about 20 IAC counts, so it would appear  
there isn't an uncontrolled vacuum leak.

Is this a sign of something wrong, something I can tune out with a  
laptop or a scantool, or just the way it's programmed?

I know the idle speed is supposed to increase with the A/C compressor  
clutch engaged, and I see that value in the PROM.  That is not a  
factor in this, though, as it has been so cold I have not needed the  
A/C.  I used it for the first time in a month yesterday, and that was  
for defrost because my windshield fogged up.

Every time I have plugged a laptop into it while it's idling in Park,  
no matter the idle speed, the Park/Neutral flag is set, like it's  
supposed to be.

Any hints will be appreciated.