If you had a small vacuum leak you would have a higher idle than normal and your Long Term fuel trims would max out and toss out a SES light. The intake manifold on this kit is pretty stelth so I really do not think that is the problem. Please refresh on the real problem , What is it idling at? and when does it die? and how often? and is there any other wierd things happening? does it start ok or does it have extended cranking time? Do you have a scanner? More info please!

 

That's not the case. A small vacuum leak will make it run rich on the top. Keep in mind, that when under boost, the vacuum leak becomes a boost leak. Assuming it's between the motor and blower like you were getting at.

This is a voice of experience too.

 

Personally .. I think some idle problems are to be expected with a cammed RADIX. When I had mine off for a short time, the idle was perfect with the cam. Blower went back on and the idle went to ****.

 

I agree w/ crash dummy, I don't think its a leak. A small leak would have a higher idle than expected. Im not getting the symptoms of an intake leake. I'm getting exactly the opposite - not enough air at idle to keep rpms up.

I do have a scanner. I've logged TB blade position, which controls idle on an 03. Its not closing up when the idle falls. Actually, the TB is open a higher % now at idle than it was pre-radix.

LTRIMS are fairly close with only changing my injector flow rate to 5.18. They are a little negative in some trim cells, and barely positive in others. Idle they are just negative. Timing is fine.

How does the MAP sensor affect idle? It was also came with the kit. But I've got a couple of extras to test out.

 

Good Point Dummy! Glad you thought of that

 

Big Tex Does your scanner show the comanded idle and the actual idle? and what is the gm/s on the air flow meter at idle? do you have a cam? The mag tune is set at 600rpm if you have a big cam it needs to be higher. I came into this a little on the late side and may have missed a few key elements so please refresh me on what you have against what is happening. If you have a bunch of aftermarket parts besides your bedrug I need to know in order to try and help.

 

Hey Blown Chevy if I wasn,t a DUMMY I would not be here now would I

 

Very true!

I think Tex is cammed and has some heads on there, I am not sure what head and cam package he is running. The truck is a 2003 SS Silvy with pretty low mileage. I know he bought the supercharger from another member and installed it on his truck. It may be possible that there is something else wrong that we missed. I know Tex took the system apart to look inside (he has destruction problems ) I have been going through assembly in my head and cant quite come up with anything that would cause the issue he is having.

Oh yeah and it has a bed rug
Thoughts?

 

Try adjusting the VE table some.

 

I did buy the kit used and the seller left all the sensors installed, which I used. I did use my MAF and throttle body. Not my MAP and EVAP.

Idle is set at 800 rpms, which should be (and has been) plenty. MAF at idle is around 1.45 pounds, throttle position is 10-11%. Before radix, it idles fine with a 750 rpm idle, MAF was 1.25 pounds and throttle position was about 9%. Truck is a 2003 silverado SS LQ9 6L mild custom comp cam, ASM headers, stock heads, no cats, LS1 Edit, flexalite fans, TR6s, Radix 3" pulley, flopro muffler.

It really seems to idle fine by itself, but when its in gear it stumbles. In park it will idle Ok unless I stab the throttle, then it may fall well past 800 rpms on the way back down. It has not set any SES lights.

My last tune I tried adjusting the VE in lower rpms as well as increasing idle air (IAC) and running airflow. It did run better with this tune, but not perfect. My real concern here - why does just adding the Radix need so much more air to keep 800 rpms? The truck only needed the higher idle speed before the radix to idle perfectly.