hanging idle!

OrangeMustangGt

Founding Member
Mar 7, 2002
1,976
0
36
Cape Cod, MA
After my car is warm, it hangs the idle around 2,000 rpm for a few secs before dropping down to ~1000 where it should be. I had it fixed on my old tune, but by mistake I wiped it. Can anyone remember what I have to change? I tried messing with the dashpot decay table, but it only seemed to have effect when not moving.....
 
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I have the same problem idle also a problem. New 331 stroker X303 cam AFR Alum heads Trick flow intake New MFA MSD dist. everything done right now have it at prof tunner for past week still have surge and idle problems infact it is getting worse. Tuner has put in new ecu still not working Any suggestions
 
After my car is warm, it hangs the idle around 2,000 rpm for a few secs before dropping down to ~1000 where it should be. I had it fixed on my old tune, but by mistake I wiped it. Can anyone remember what I have to change? I tried messing with the dashpot decay table, but it only seemed to have effect when not moving.....

Kyle

Several thoughts about the nagging issue you speak of here

I can say I've seen it crop up on ALL tunes I have built in the past :(

I've ran tunes based off of t4m0 & j4j1

Its been my finding its more likely to happen on the t4m0 :shrug:

Idle issues can be VERY frustrating as SO MANY things control it :crazy:

First things first :D
As like most different areas in the tune :)
It is an ... ABSOLUTE MUST ... to make sure
You ain't got mechanical junk hosin up your tuning efforts :chair:

In this case ...
Make sure the t b stop screw is not holding the blade too far out :Word:
and
You don't have the tb bleed screw too far out ;)

Look in these areas of the tune to help
and
I must confess ... I've forgotten a bunch of the specific details :(
but
I'll do the best I can to describe from memory

Scalar ... I think ... Throttle Body airflow
ISC duty cycle ... forget where it is

This one table will make a big difference on idle

Neutral Idle Airflow or something close to that :shrug:

Basically ... You use this table to reflect airflow at different rpm

In a nutshell you datalog at different rpm's and plug in the data
seen from the dl file

You can use feeler gauges to up the idle speed while testing

Sorry to be so generic with my help but I just haven't done any tuning
for so long and I've just lost a lot of that stuff but all this stuff is
documented all over the tuning forums

and

If you search back WAY BACK THERE when I was involved ......

I've documented all that junk on our site more than once ;)
but it is gonna be 2 to 4 years back :shrug:

Might be that I covered this stuff on my site :scratch:
but
I can't remember a lot about what I put up there as well :rlaugh:

Now that I think about it
seems like
Wes talked about that table like maybe within the past month :nice:

anyway ...
maybe that will get you started in the right direction my friend :)

Grady