Ive tuned my truck for idle and have the in park and in gear idle set and tuned where i want it in hptuners and the truck will idle correctly in gear but in p/n idles about 1000-1100 over the tuned rpm setting. Any ideas what might be causing this? Ive already checked for vacuum leaks and there are none. Im extremly stumped.

 

idle airflow? Is P/N lower than D?

 

Post tune

 

If it's 1000rpm over the correct idle value in gear, I'd be looking at something mechanical, like a sticky IAC... Something in the tune causing that would be too painfully obvious to miss.

 

Here's the tune, im really new to tuning just got the software and Im just trying to get it to idle for now. I had a custom tune put in the truck when it had the 4.8 so thats why the trans tune is different. I had it tuned to shift firmer4.8l custom tune.hpt and when the truck is first cranked it idles correctly and then jumps up to about 1600-1900 after a few seconds

 

Will take a look at it when I get out of work and let you know.

 

how big is the cam you have? is it still a 4.8?

need more info, like

full cam specs and all mods done to truck and size of engine.

 

its a 5.3l with a comp cams xr259hr cam, 259/265 .515/.522 lift at .050 its 206/212, cold air intake, hollowed out cats, cat back exhuast l33 flattop piston pac racing valvesprings valve job on 862 headsbrand new bearings all the way around. just finsisehd rebuilding the motor ive run it for maybe 45 minutes combined.

 

The first tune has some weird stuff going on...the P/N idle speed is ~300rpm higher than the in gear RPM, which should be oppisite if anything. Also the base airflow is the same for in gear and park, which is probably why it revs up.

That file roadkill posted should work much better.

 

Your base running idle airflow is close to double of stock. That is another reason your truck is idling so high.