After a heads/cam/intake swap, I had the car tuned by Solomon. He set the idle to 800, but the car is idling at 900+ or so in park/neutral, and it pulls against the brakes in drive. No vac leaks or anything out of sorts (other than some noisy rockers..). The throttle body is the one that came on the car, but I put on a new gasket and cleaned it up while it was off. I did the TPS reset and it had no effect. Cables are not bound up. Linkage is free and the throttle blades are closing against the stop.

The tuner is telling me to adjust the throttle stop, the ICM, and TPS to fix this, but everything I've read says that the idle is locked in the tune. (The torque converter also isn't locking up, but that's another issue entirely)

Any suggestions?
Thx

What TB? I went through this with an aftermarket TB. I had issues with the blades closing against the stop when the car was off, but not when it's on. Stock TB ran perfect.

Is it 900 rpm on the tach or via your scanning software. Maybe the tach is off.

I had the same issue when I did my very first head cam swap on my 96 Impala. Same exact symptoms as yours. Turned out to be my torque converter, which was still stock. Replaced it with a 3200 stall an car idled and ran normal and there was no more pulling on the brakes. Had to get a retune for the new converter as well. Is yours still stock? That may be your issue if it is.

No, I had a 2800 converter in it. Mine was a holly that was fucked up from the get go. I'm pretty sure the shaft the butterflies sat on was bent/binding somewhere, it was used and the guy I bought it from had the same problem (he told be AFTER I bought it).

Stock throttle body, and stock torque converter. A 2800-3k stall is on the table, as are 3.42's

Your tach could be off. I know mine is off a good bit. With my MSD box and 2 step, the launch is set at 3000 and the regular is 6200, it's off by about 1000. When I'm hitting the two step at a 3k rated module, my tach is EXACTLY on 4K. So maybe yours is off a little bit, unless you've noted by ear it's idling differently. I would check the IAC again. I just recently fixed my idling issue with just replacing the IAC and while the IAC was out I meticulously cleaned the TB.

The tuner set the idle to 800 - in gear or not, and a scanner shows the idle to be around 830-850, so its pretty much doing what it has been told to do. The car is an auto, so it should be idling at 650 in park/neutral, and 500 in gear. No wonder its pulling against the torque converter at lights...

That's really low IMO.

Can you clarify? The factory sets the auto to idle much lower than the manual. Now, if it would idle at all with this cam, at that RPM, is another question entirely, and I am not too sure it would!

If you say that Solomon set the idle in the tune at 800 and you are seeing 830-850 on the scan tool then I'd say you're right where you need to be...or at least where Solomon is commanding it to be. As far as a H/C/I car idling at 650 Park/Neutral and 500 in gear, good luck. Not knowing any specifics, I'd say a 800rpm idle is not bad. Solomon is a smart guy, you'll be satisfied with his tune I'm willing to bet.

Agreed with Kris.

It's been so long....but I'm pretty sure that even when stock, my '96 Impala idled around 650 RPMs. With heads/cam, your idle will need to be at LEAST 800 RPMs.

Now....even pulling against the converter shouldn't be a huge issue. My question.....you still running OEM brakes? When was the last time you installed new pads?

KW

All Kore3 C5/C6 Z06 brakes and calipers. All new-ish pads.

Looking at the logs told me that the bank-2 O2 sensor was seeing a lot of extra air, so I went leak hunting. Found the EGR pipe coming from the header wasn't tight to the manifold. Tightened that up and the idle dropped down a bit, ICM #'s dropped down, and it stopped pulling so hard. MPG's went up as well.

Good deal!!

KW