AdsoYo

He didn't mention and I didn't think to ask. I just assumed they were out of 2-3-4-7

Cam is 224/230 duration @.050", 0.530" lift intake side, 0.540" exhaust side

AdsoYo

I went scouring the internet for someone to help with the tune. Managed to find someone on hptuners forums who's programmed a few 24x LT1's. He took a look at my tune and said it was really rough. He said it had the stock LS1 fueling and spark tables. This is more than a little infuriating since I paid pcmforless $250 for it. He reprogrammed it for an LT1 and my car runs SO MUCH BETTER. Acceleration is especially smooth, idle and part throttle cruise is still a little rough.

This brings me to a new question: The car idles quite high, like 1700-1800 rpm. If the car sits long enough, the idle will eventually come down to about 850 and when it does, it's quick. It's not a gradual reduction of idle, it's 1800 then snaps down to 850. Also when it's idling at 850, it sounds like it's almost dying. Like it's having a lot of trouble maintaining 850. Also if I blip the throttle, like give it a quick press, the rpm will stay up at 1800 for a while again then quickly drop to 850 like before.

I don't think it's a vacuum leak because the idle eventually drops to where it should be. I don't think the throttle is sticking either. I'm going to drive it today and keep an eye on TPS/IAC, although it worked fine before 24x.

AdsoYo

I think I found a part of the idle problem. With the throttle body closed, I'm getting 0.74v. The tune I was sent requires the volts be at 0.63. I tried backing out the screw but I could only get it to 0.68 and the blades were sticking. Is there anything we can do about this?

To be clear, I don't own hptuners. A local shop that has it has been gracious enough to help out. So I don't know the interface or anything.

ACE1252

There is a function for the LS1 PCM's that allow for a "soft landing" so to speak. For example, if you blip it to 5000, when it comes back down, it will hang a few hundred RPM above the idle point for a sec or two then settle in at the target idle. I remember seeing this in Greg's advanced video. I'll take another look at it tonight to refresh myself on what he said.

I would quiz the gentleman that nailed your programming issue.

Do a search for TPS voltage. Injuneer has several threads outlining where the TPS voltage needs to be. I would not try to change it(the voltage...leave it at stock LT1 settings for now). I think the program needs to be tweaked some more(but I don't know for certain).