IAC flaring on EFI Hardware Throttle Body

[Dylan]

It will need an LS model IAC solenoid they're a larger diameter pintle

[someguy360]

It will need an LS model IAC solenoid they're a larger diameter pintle

Hmmm, that wouldn't change my symptoms though would it? the problem is that the IAC is opening too far not that it's not sealing up at idle. For example if I put it in drive it will open the IAC up to around 150 steps for 10-20 seconds then drops down to 10-15 steps and idles correctly, meaning it's sealing up ok when it's closing.

The IAC that EFI Hardware sells for these TB's are the smaller pintle ones. (https://www.efihardware.com/products/38 ... otor-VN-V6)

[VK_3800]

Given the number of steps you're seeing it seems unlikely that there is a physical issue, you just need to tune it not to open so far. As long as the pintle seats correctly and it has a fairly consistent/incremental rate of opening then the overall hole size doesn't matter (other than noise).

There are a lot of IAC settings that can help when using a bigger cam (the image is $12P but I imagine there are similar in $11P). In particular the maximum MAP load limit scalar and idle MAP threshold table can make a big difference as to which idle mode it uses - this engine idled at ~65-70kPa and the idle would run away with factory settings. There's a thread around here somewhere that explains how this works in some more detail.

12P_IAC.png

[VK_3800]

Might be this one?
viewtopic.php?p=13550#p13550

and?
viewtopic.php?p=53084#p53084

[someguy360]

Thanks mate much appreciated, looks like I'm getting closer, will these adjustments tomorrow!

[someguy360]

Just for reference if anyone else has similar issues.

The Maximum MAP load limit and Idle Map Threshold tables seemed to fix it, it was set to around 40kpa and my engine was idling as I was playing with it at around 75kpa so no wonder it was struggling.

Seems a lot more stable now.

Thanks everyone

[immortality]

Good to hear it's sorted.