adjusting LS3 idle speed

[Champster]

I have successfully installed the donor LS3/TR6060 into my '68 Camaro and it runs great. The only thing I would like to change is the idle speed. It idles around 1000-1100 and I would like it to be more like 700-800.

What is a normal idle rpm of the 435hp LS3? Would running it at say 750 cause me a problem when the Vintage Air compressor kicks in??? I don't have the AC routed through the computer to raise the idle when the AC turns on.

Lastly, do I have to have it hooked up to the EFI Live computer to adjust the idle speed?

Thanks for you thoughts
Paul

[1989GTA]

I have mine set to idle at 800rpm. I guess it depends on the camshaft and your comfort level. I have HP Tuners and use that to adjust the idle speed. So yes your EFI Live will do the trick. I also have A/C and it is not hooked up to the ECM either. When the compressor kicks in I don't notice a thing. Either in drive or neutral.

[Champster]

I have mine set to idle at 800rpm. I guess it depends on the camshaft and your comfort level. I have HP Tuners and use that to adjust the idle speed. So yes your EFI Live will do the trick. I also have A/C and it is not hooked up to the ECM either. When the compressor kicks in I don't notice a thing. Either in drive or neutral.

Excellent answer! That is what I was hoping I'd hear. I might have misspoke though. I don't have EFI Live (wish I did). How much is HP Tuners?

Thanks
Paul

[1989GTA]

I have not checked the prices lately. There are two levels depending on your needs. You can do a search and get the latest pricing.

[fleming23]

Excellent answer! That is what I was hoping I'd hear. I might have misspoke though. I don't have EFI Live (wish I did). How much is HP Tuners?

Thanks
Paul

Pretty expensive if all you are trying to do is adjust idle. Your best bet is to find someone who already has it and get them to buy a license for your ECM which should only be $100. The actual program (hardware and software) starts at $499 if I recall correctly.

[andrewb70]

Make sure that you don't have a vacuum leak.

Andrew

[Champster]

Make sure that you don't have a vacuum leak.

Andrew

Thank you Andrew. Could this include a leak in the air inlet between the MAF sensor and the intake manifold? I have a cold air tube that doesn't have a rubber coupler over the junction yet I am 97.573399% sure that is it air tight.

Thanks
Paul

[andrewb70]

Thank you Andrew. Could this include a leak in the air inlet between the MAF sensor and the intake manifold? I have a cold air tube that doesn't have a rubber coupler over the junction yet I am 97.573399% sure that is it air tight.

Thanks
Paul

Paul,

I could give you a "male" answer, but the truth is that I don't know. Ideally you need to see what the TB is doing at idle. If the commanded idle speed is say 800, but you are at 1000, and the TB is closed, then there is a vacuum leak after the TB.

If there is a leak in the intake tube, after the MAF that would certainly throw off the tuning, but I don't know if that effects idle speed in the way that you're experiencing.

Andrew