IAC on turbo v8 Help needed

[VX L67 Getrag]

Thing I don't understand is why it's changed since going boosted!

What plumbing has changed around the area?

Do you have logs of it before turbo went on?

How much did you pull apart when putting turbo on?

[vp304]

Only things changed on engine was balance lines fitted to the top of the gas converters thats it, and some jetting in the gas carb was made smaller, as when the turbo comes on boost it pressuries the gas converters to feed more gas to the gas throttle body. As you can see in the pic page 3 or 4 i think of the iac block the hoses going from tb to iac block are not overly big. Its got me stuffed when i disconect the iac it makes no diffrence. I would think on a normal car im guesing it would shut and the car would want to stall

[vp304]

Greg only log i have na days is with win aldl from around 4 years ago

[antus]

So ecu is spark only? If so it sounds like your trouble might be lpg fueling related. Guess the cold enrichment in the ecu isnt going to do anything?

[vp304]

Yeah pritty much timing only. Cant control fuel

[vn5000]

To check the iac closes all the way ,you can put it in diag mode key on eng off and it will close the iac fully .Then disconnect iac plug and start the motor.If it wont idle or its idle is to low ,adjust idle screw till desired idle.Then disconnect ecu or batt so ecu learns new tps minimum and start .If all is working well you should have no or low iac steps.

[vp304]

Vn5000 is that done on a warm engine?

[vn5000]

yeah ,warm engine.Just a test that may help to see whats going on and if the iac can shut all the way.You should find that you cant blow any air through it.

[vp304]

Will try it tomorow. when disconecting the iac and starting the car do i leave it in diagnostic mode?

[vn5000]

yeah .remove the diag jumper after disconnecting iac motor.