idle tuning

[ga2001532]

i started tuning my car and i think am getting the hang of it but when i tried to get stft and ltft close to zero during idle it raised my idle to around 1200-1400, my stft and ltft were maxed out lean before hand and it idled fine, i got my stft to zero and the ltft is still in the sevenish range, but what can i do to get my idle back down. the commanded idle is around 900. makes it hard to shift with a higher idle. i have a log but for some reason logging with powrtuners it losses rpm.

[SappySE107]

What cam? You need to drive around and then tune idle once its warmed up. RPM shouldn't be affected by adjusting the idle fueling.

[robertisaar]

even then, i would think the IAC and idle spark compensation would bring it back down.

[3400-95-Modified]

Log your IAC count and see what it is... If he's commanding 900 and getting 1200 or higher than there is a VAC leak somewhere.

what version of DHP are you using? and how is the logging setup? Direct to CSV? or internal Log file?

[ga2001532]

Stock 3500 cam. It was warmed up all the way. I will log the iac, I forgot to add that one, and uvscan likes to blue screen on me while logging. Am thinking vac leak but it idles stable. It idled low before I started changing the ve and mad table in the idle range. Every time I bumped the ve up it lowered the ltft but my idle rose alittle. Right when it starts it idles right but then the stft starts moving and the idle goes up. I now changed it to export to csv see if that helps the logs. Does any one of a ported with heads bin file I could compare. I had to add a lot to the idle area to get the trims down.

[3400-95-Modified]

VAC leak will still idle stable, just higher than commanded usually and you'll have a 0 IAC count. Which version of UVScan? I have one that I use regularly and never locks up on me.

[ga2001532]

I guess I will just spray the lines and see if I have a leak

[ga2001532]

Yea my iac goes to zero, so either its a leak or the sensor.

[ga2001532]

I can't find a leak but if I just pull the pcv out while it runs it idles better. Keeping it hooked to the vac line. Put the pcv back in the valve cover and the idle goes up

[ga2001532]

Now after playing with things. Went back to my orignail bin. Stock settings. My iac is sitting at 20 while my idle is 2000 now.

[ga2001532]

Ugh I think the tune just went bad. Put the old one back on. Idle trims way lean but it idles fine went from 2000 rpm idle to the 900 just like that. But I bet once I work the fuel trims back the idle will go.up

[SappySE107]

How are you tuning? Care to upload the files?

[ga2001532]

Am using dhp, for idling I just change the numbers my self but I found what was bad. The tb, one bolt was not all the way tight. Am out driving and logging now. I will post up a better log and bin.

[ga2001532]

well i guess it was a vac leak after all. idles good right now, just need to fine tune the ve and maf table to smooth it out. well pretty much restart the tune again. my last log lost the rpms. it shows it in the gauge the entire time. i guess uninstall and reinstall, i need to figure out uvscan to. but it sucks getting blue screened and losing the log.

[3400-95-Modified]

I'll get you some UVScan info, and yeah any vac leak will just destroy a tune so it's best to start over again, an honestly it's necessary.