IAC steps w/ 3400 5spd turbo

[scott0999]

for quite some time its been stalling. today i finally got off my ass and decided to check the iac steps. i did an idle relearn and datalogged once it warmed up. it was at 32 steps. when the fan came on it would go up to 40 and back down to 32 again

it seemed a bit high so I messed with the idle set screw a bit. I managed to get it down to 28 steps but no less. the chip im using has a desired idle of 975 and the iac steps are higher than a stock tgp chip too.

I was thinking about getting a stock tgp bin w/5spd patch and copying the desired idle and iac steps onto my chip. sound like a good idea?

[flybynite]

Yes you will half to look over a n/a 5speed bin and change the IAC settings to match.On a properly tuned car you will have 0 steps at idle.Also look for the THROTTLE FOLLOWER VS MPH This will help as your slowing down with the clutch in.Also make sure your not to rich when your stalling.Thats the main reason these cars surge and stall at or around idle.Later

[TGPilot]

On a properly tuned car you will have 0 steps at idle.Also look for the THROTTLE FOLLOWER VS MPH This will help as your slowing down with the clutch in.Also make sure your not to rich when your stalling.Thats the main reason these cars surge and stall at or around idle.Later

Adam,

With the standalone ECU manufacturers I work/deal/trained with they have all said that you want at least 25-30 steps on a 210 step GM IAC. This will allow for idle fluctuations due to weather, altitude changes, small vac leaks, etc. If he is dead on 0 then the weather or out door temp changes he may end up with a super high idle or no idle that can not adjust because the only thing allowing air in is the throttle plate breach.

I had always made sure I had 40 steps before they said that because of what I had heard and learned. With my chip it normally sits around 36 when warm and idle.

Any reason why 0 is the "needed"?

-Kenny

[flybynite]

I have found that 0 steps at idle works best for me.I look at the IAC as a vacuum leak,thats all it is.It's used for cold and hot start up and some off throttle situations.If your butterflies are adjusted right you wont have any problems with weather.0 steps at idle also helps with large camshafts,it will keep them from surging and stalling at idle.Cams with lots of overlap will put fresh air in your exhaust and wig out the o2 sensor reeking havoc on the IAC.I know our TGPs don't have much of a cam but thats the way I've always done it and I've never had any complaint's.Most of the cars I've tuned over the years have had solid roller cams that would go BUMP in the nite,the TGP is by far the most tame but it also has 0 steps at idle with no problems other than a leaking radiator.I also had to teach myself how to tune cars,I never had ECU manufactures to help me.I would THINK they would know more about this stuff than I do :icon_redface:    Later...Adam

[TGPilot]

Well it made sense to me after I read what you posted about 0 steps. I am going to try it in the TGP for shites and giggles. ;)