Help With RPM Dip When Going To Idle, LS3 DBW TB, No VSS

[scottr126]

Hi guys, I am hoping someone can help me out here. I have a 1968 Camaro with a 408 LS and TH400 transmission, no VSS, no A/C, and an LS3 DBW throttle body.

I am having an issue where anytime it returns to idle the RPM dips down to about 400 and sometimes will stall out before settling back to my set idle of 700 in drive and 650 in park.

One of my issues is I have no VSS so I am not sure which parameters will help me out here since vehicle speed is always 0.

I attached my tune file and a log of this happening. You can see where I will give it a little rev and then it dips down after.

[01SLPSSM6]

This is what you need for the VSS
http://www.dakotadigital.com/index.c...rod/prd916.htm
You will also need to wire up a switch so the pcm knows if its in park, neutral or in gear. Pcm connector 1 pin 32, double check that pin number.

You're base running airflow numbers will definitely need to be lowered after you get the vss and switch wired up.

[scottr126]

The car does have a Park/Drive switch. In the log you can see when its in park it calls for 650 rpm idle and when it goes into drive it calls for a 700 rpm idle.

I will check out the VSS adapter. Thanks!

[01SLPSSM6]

Ok sorry I didn't check the log. Just wanted to mention in case you didn't have one.