Can't bring idle down. so pulling my hair out for fun instead.

[MADWHIP]

Hi All,
Ok so I have a 2000 VT Holden with a LS1 it has a cheap alloy intake manifold and a cheap 102mm throttle body on it.TB blade set to lowest rpm and sensor unplug reset carried out. I can't get the idle below 1300ishrpm. I can't find any leaks. But if I command zero idle air flow it makes no difference at all. I expected the car would die once start up air flow had decayed. If I add base running idle airflow I can raise the rpm. When it's cold it starts at around 950rpm and slowly rises. I'm sure the issue lies with the cheap throttle body but I cant fit a standard one on to the big alloy intake to test.
I will attach a copy of the tune and log and a copy of the stock tune. I would really appreciate it if someone has an idea or a process to confirm the cheap parts are at fault.
Any comments welcome.

[5FDP]

Not sure if it'll make a difference but you do want the maf fail high to be at 0hz to revert straight to speed density. Then just remove your MAF pids.

I've not dealt with the intake setup you have, so much much else for me to say.

[MADWHIP]

Well spotted 5FDP. It made no change

[GHuggins]

I'm going to say what I personally hate being told, so don't get mad at me Keep it Simple... Can almost bet it's an air leak... Even smoke testing won't always show leaks under engine running environments... I had one one time that I chased and chased doing exactly what yours is doing - showed almost no smoke when tested - pulled intake anyway - found head stud nuts holding the intake up - intake actually rocked on them - only really showed up for some reason when the engine was hotter? Sealed intake - problem gone...

As long as you don't have a hole in the throttle plate and the plate is closing all the way and the iac is closing correctly if equipped then it has to be getting the necessary air to run from somewhere

Anyway, something to think about...

[MADWHIP]

GHuggins I'm thinking the same thing just hoping I was missing something else. Thanks for taking the time to respond.

[Mr. Smith]

Random half-asleep thoughts..
- it isn't tuned correctly to suit the oversized intake..
- your TPS could (also) be out of whack.. does it read around 0.5v at idle and 4.5v at WOT?..
- does your T/B have that rubber-gasket behind it or is it just metal-to-metal contact with the intake manifold?..
- have you sprayed carb cleaner all around the intake manifold and T/B while idling?..
- I like the thread title..
- something is "reversed".. your idle starts to climb from cold instead of lower..
- does anyone else have the same intake setup + problem?..
- did you buy the VT with the intake already on it + with this idle problem or did the problem start after you tuned it?..
- are you running an air filter?..
- why does your MAF sit on 2.2g/s?..
- why does your TPS sit on 0?..
- what would happen to the revs if you covered 57.2% of the air intake with your hands or something?..
- I need to have sex with Megan Fox.. tomorrow..
- I compared your tune to a stock LS1 Camaro and Vette and noticed your Firing Order "starts at a different time"..
- have you compared your tune to other early LS1s with big aftermarket intakes?..

[MADWHIP]

Ghuggins wins, it has a leak under the intake, think I'll have to grind the bolts down or swap valley plate out for one with countersunk holes.
Thanks guys.

[Exidous]

Many of the aftermarket intakes do not leave room for the factory bolts. Pan head hex bolts must be used with the FAST intakes (as an example) otherwise they leak quite badly.

[Mr. Smith]

Ghuggins wins, it has a leak under the intake, think I'll have to grind the bolts down or swap valley plate out for one with countersunk holes.
Thanks guys.

Hey hey now.. I also brought that up too (my #4 qn/step/note). When I mentioned spraying carb cleaner all around your intake and t/b, it wasn't for cleaning/polishing purposes lol.

So did you sort it out?
And more importantly, do I get a medal/prize/award?

[SultanHassanMasTuning]

v12 SD.hpt


here is your SD setup