My truck has an intermintant idle problem. Every now and then the idle of the truck will dip below 450 rpm's and almost die. It doesnt happen all the time just ocasionaly when I let off the throttle at low speeds or at stop signs. I had Allen Nelson look at the tune, but he didnt come up with anything. Any ideas? Maybe vacuum leak?

 

If this is not related to the A/C coming on or any other power draw on the engine, I would have him look at your stall saver settings. If he raised your idle to say 800, and the stock stall saver is still set at 450 or so to account for a stock idle of 550, then your truck has more room to stumble before the PCM tries to compensate. Whatever your idle is, set your stall saver to about 200rpm below that. This helped me quite a bit.

If he didnt adjust your idle at all then I have to ask, did this start right after the tune went in? Any other mods at the same time?

 

I would have to say that it happened some time after the radix install, but not right after maybe a couple of weeks. The A/C is running a lot lately and I sm still having problems with the BCM throwing HVAC codes.

 

The stalling doesnt happen when the A/C compressor kicks on does it?

Did the cam go in the same time the radix went on?

 

I dont think so .

No the cam went in about 2 months later. The low idle was happening before the cam and after.

 

Is your Radix new or is it an older one that had the throttle cable bracket mounted to the top of the J tube?

 

New with the electronic TB.

 

I had the exact same issue with my bone stock 04 sierra. It would dip low in rpm for a moment, like a quick surge. This would happen even if the A/C was off. Never found out what the problem was and didn't worry much. Do a search and see if you come up with anything; someone mentioned something about an IAC adjustment in a search I did a while back.