IAC on turbo v8 Help needed

[vp304]

Hey guys have just got my vp commodore v8 up and running with the turbo bolted up running good on 12p 2bar tune done about 300k's in the car.
Now the car is on straight gas, gas research so it has a gas research throttle body with the holden iac mounted on a seprate block . Takes air for the iac from before and after the butterfly blade just like factory, but it also has a little lpg feed from the gas converter low pressure side to the iac, which can be jetted also.

Now this setup ive had running on the car for around 3-4 years working great. The delco pritty much just does the timing and a few other small things.

Since ive turboed the car the iac is giving me some grief. Its open around 100-120 steps all the time. So when the car is cold its idiling low as crap cause i dont think the iac can open up anymore. Once the car warms up the idle is perfect, but the iac is still at around 100-120 steps.

Now i have tried to open up my throttle body to try and close the iac. Disconected battery ,dc iac hold revs over 3000 tried all the stuff other people have told me to try but it makes no diffrence???
Like i said the iac was working perfect before hand on the na setup now i pulled the car of the road for 3 weeks add some boost and its causing grief.

Couple of other things.
I was just running modified 5d tune before on the na setup
Tps shows 0% at idle and looks like its working.
Will upload a log in a few mins if that is of any help to you guys


Any info will be appreciated thanks guys

[VX L67 Getrag]

Don't suppose you checked your fault codes?

You have 4:
tps
Idle error
cam position(I think from memory)
& knock sensor

Fix these & then issue might correct it self!

[vp304]

cam position no such thing on a holden v8 that i know off
i think thats on vr v6

idle im guesing is iac being open so much

knock sensor i was told the false knock counts are cause its turned off?
only shows proper data when its turned on??

[VX L67 Getrag]

look at your logs it tells you whats in red is set as fault!

[vp304]

At work at the moment will look on tuner pro when i get home. Im a bit of a n00b at it all. Were should i be looking fir these faults highlighted in red? Il upload the tune also. Im99% shore i have the knock sensor disabeled

[Holden202T]

open up the item lists and it is at the bottom of the list usually.

[antus]

Looking at your logs its showing no knock retard, so I think that knock sensor config is OK. The fact you are seeing TPS stuck and IAC errors makes me suspect of the wiring out to your TB. I'd be checking that. Either the IAC is fully open and not enough air is getting in (in which case you have a TPS issue, and throttle stop screw issue or similar) or the wiring out to that part of the system is faulty and the IAC isnt opening even though the ecu is trying, and the TPS signal is also not getting back to the ECU. You might find the 1 wiring fix clears both DTC 19 and DTC 35.

Im not sure how relevant the DTC 46 No Ref Pulses is? The 'during cranking' part throws me out and ive not had that one? Logs are showing believable RPM, so thats a good thing.

[vp304]

I didnt think it was retarding timing as on only 7psi i bet a vx ss manual with exhaust and a ba xr8 with exhaust, and can stick pritty close to my mates vz clubsport 6lt with tune otr full exhaust and close ratio box
I am fitting a knock sensor soon tho.

The tps showing 0% at idle cause its not showing 1-2% etc could that be a problem? Il check the wiring over as the tps an iac are the only 2 extended. They were done a long time ago.
The throttle body is closed all the way at idle . Ie throttle screw unscrewed

I drove the car set the mixtures to .9s for cruise and idle and .8 lambda on full throttle. Made shore it was retarding timing on boost and have done about 300ks in the car so far.

[antus]

I checked your log again, I can see there is a signal there for tps, but its low (66% near the start, not passing 50% later on). Im not an expert in error codes so will see what others say. When I saw that symptom on my mates 240z there was no 'stuck' error code, and the way we had it set up it was not opening the TB far enough. We fixed it by adjusting how we had the accelerator cable set up.

[vp304]

Antus i think i had this problem when it was na as the throttle body is not standard it was a little off ie didnt go more than about 88% throttle position when loging in the old days threw aldl. I never worried about it tho as the car drove fine.