Holding RPM

[Picto]

Hi, hopefully someone might be able to help me with this.

Everytime i seem to do a cam or blower i get a holding rpm condition as coasting down. the car will hold rpm all the way to stand still and a few seconds after. It normally starts to happen after about 20mins of driving and continues from there. in autos it seems to be very pushy as your driving like its holding the revs up while coasting. I've tried everything but i'm now at the point where it's driving me crazy.

Thanks

[WeathermanShawn]

Sounds like an IAC issue. I am not sure about the cam/blower connection, but if I put too much air into 'Desired Airflow', 'Throttle Cracker', and/or 'Throttle Follower' my car will 'coast' also. Also check you decay rates.

The only time I have had a RPM issue is when I inadvertently put too much Spark Advance into the Base Spark and Park/Neutral . That will jack it up, but I only noticed it when coasting when holding the car the Neutral (M6). So, normally I drop Spark in those Tables to prevent that issue.

Not sure what else it could be. If it is only in an Auto Trans..there might be a clue there.

Good luck..

[Picto]

They are the main tables that i have been looking in, i have also adjusted spark tables to try and correct the problem but as of far no luck. The problem happens in both M6 and auto, but is more noticable in the M6. From what i can see from the logs it looks like the condition happens on coasting down till the vehicle come to a complete stop and then after a few seconds drops into its idle condition. Its almost like it speed related then rpm related becuase like i said once your stopped for a few seconds it drops into idle and is fine and idles away like a normal car. As for the cam/blower connection i'm basicly putting it down to something i'm changing in the file once modded from stock.

[5.7ute]

Log the various airflow pids & you will see what table or tables are causing the rev's to hang.

[Picto]

i will log and see what happens, i'm doing a hvt1900 blower next so i will give it a go.
Anything you that i should be logging that i may not have been?

Thanks for the advice

[WeathermanShawn]

If I am doing just an 'IAC' type log..I drop all my other PIDS and pick every IAC-related PID I can find. That way you can keep the channels under 24.

As a hint, I try to dial in the Desired Air to about 7-8 g/s at 176F or higher (depends on RAGIG, etc). I use the 2002 ZO6 TC Table, and use SSpDmon's Idle Tutorial Throttle Follower values and decay rates.

IMO, the problem is usually too much air in the TC..but logging is the only way to know for sure.

Good luck. Enjoy your tune and log..

[RevGTO]

Hanging idle and "cruise control" often occur after reflashing as the PCM relearns its idle settings. It takes many ignition cycles to settle down unless you do an idle reset. After a cam or blower you've made a major change to the idle parameters and you will have to tune for that as described above.