$12p Coasting idle speed

[zspanners]

Hi Guys, having issues with a Modified VP V8 Auto using a $12p File.
Coasting idle speed too high with closed throttle and coasting in gear, I do not seem to be able to find the parameter to be able to adjust this.
The IAC steps are too high if the vehicle is rolling ie speed input reading.
Any clues or tips from anyone please.

zspanners

[immortality]

The engine idle speed when coasting in gear would be related to the transmission. What sort of coasting speeds are you talking about?

How much line pressure are running in the trans at 0 TPS?

[vlad01]

does it work like that? VP don't have electronic autos. I don't think there is any form of gearbox tuning electronically on those models?

The do have TC lock. Can that be something to do with it?

[Jayme]

what are the IAC steps at idle?? could just be the throttle plate adjustment screw screwed up too high. you generally want around 30ish steps at a hot idle.

[Holden202T]

more information whats been done to the motor / gearbox ?

firstly there is idle speed paramaters for in gear and park/neutral etc, check these to make sure they are all set right (even the manual ones)

also as per jayme make sure hot idle iac is low enough, i'd even go to 20 if you want to.

i have also tuned a few cammed v8's that want to idle at 1000rpm, and with a stockish converter that seems to make it want to push a bit at zero throttle coasting .... i had to change some of the IAC settings ....

theres also some settings you can change for iac step changes too, but try the above first.

[zspanners]

Hi , Yes been through Hot idle throttle opening and iac steps ,lt runs at 7-9 steps in neutral 70'ish in drive foot on the brake.
Quite a large cam no specs , 355 stroker 23Lb injectors, stock intake manifold , pod filter ,extractors and single 3.0 " exhaust , shift kitted rebuilt original auto , 2800 stall.

Been through all of the usual settings and this thing drives on at 2000 RPM and 60 KPH and 0 throttle.

zspanners.

[Jayme]

if you close off the throttle stop screw a turn or so, that will bring up the hot idle IAC steps, try 30 or 40 steps at hot idle. this will also mean that since the IAC will stay at the same amount of steps as before, while coasting, the throttle will be closed more so less air will go into the engine and your problem shouldnt be as bad.

[VL400]

Start with what Jayme suggests with the throttle stop screw but the IAC steps are learnt as part of the closed loop idle speed control. Its then used as the base idle steps which things get added to, but there are limits to it all and with the MAP changes due to the cam it might need some tweaks if its adding too many steps.

[Holden202T]

yeah I was thinking 60 odd steps change in drive, that's heaps! must loose a crapload of vacuum in gear .....

what rpm is it idling at in drive happily ?

[Dylan]

I just a had win with my 304, I tried running the closed throttle VE. Its now a whole different car made a huge difference.
I tried it in the past with Kalmaker but never made this much difference.

Could be worth a try?