the.hamburglar

ok i know this has been covered a million times and i have done a search. my idle is constantly bouncing between 1000 and 1200. i have a new crome basemap in there right now that claims to have a smooth idle. my car before the turbo was on had a smooth idle so i dont understand how it has suddenly be the FITV or IACV. i think it has something to do with the turbo i just installed. however when i first start the car and let it warm up for a few minutes it runs awsome, its just when i drive it down the street and stop to let it idle that it surges..weird

1. could it be ralated to any vacuum sources not hooked up tight? i know it could be a vacuum leak but im positive i have everything hooked up tight.
2. could it be because of a 3" open down pipe? maybe there is not enough back pressure? im doing a 2.5" tommorow with a quite stock like muffler. ill keep you posted.
3. im just waiting until my 12" slim fan gets here because shes running a tad hot. could it be because of this at idle?
4. fauly map sensor...doesnt like so see some ways i have the vacuum lines run??? im just thinking of possibilites
5. shoud i increase the duty cycle of the IACV or decrese it to get the smooth idle. its at 0 right now.

thanks

Joseph Davis

Could be air in the TB/IACV area, that causes a small surge like you describe; FIT-V typically only causes big surges. You could also be hammering against the 1300 rpm fuel cut @ idle... try to close the throttle stop and/or air bleed a bit and see if that doesn't smooth things out.

Good luck with that "good idle basemap" stuff, it generally doesn't work that way. For best results your idle has to be tuned. 60-70% of the TBs I touch have been molested from stock, the throttle stop or air bleed has been fiddled and need to be set exactly as the car your basemap was taken from was set. If you are running a different (bigger) TB, then you have to tune your idle. If you are running a GM 3 bar, known for a little sloppy calibration between sensors in the idle area, then you have to tune your idle. Different CR, or cams, from the engine that the basemap was derived from, causing the engine to want to displace more air at idle will require you to tune your idle.

iNERtIA

what do u mean by air in the tb/iacv? i have the same prob although, not all the time. and when it does it, i try to choke it by dragging the clutch pedal a bit then it stops.

Joseph Davis

Air in the coolant lines through the TB and IACV.

iNERtIA

^how exactly do i get rid of that? just open the rad cap and run it? i have a obd2 b18c

HiProfile

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by the.hamburglar &raquo;</TD></TR><TR><TD CLASS="quote">1. could it be ralated to any vacuum sources not hooked up tight? i know it could be a vacuum leak but im positive i have everything hooked up tight.</TD></TR></TABLE>

Thats the most common problem. For example, even a small leak in your bov's diaphram will allow enough air to make it surge. To give you an idea, a .5mm gap around the throttle plate will make it surge, as happened when I tried an oem 60mm plate in a tb I bored to 60.5mm.

The way you are supposed to set the idle is with all accessories off, engine warm, and iacv plug off, then set to 420rpm via the adjustment screw. Turn off ignition, reset ecu for 10+ seconds, then enjoy a solid 600rpm idle.

Joseph Davis

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HiProfile &raquo;</TD></TR><TR><TD CLASS="quote">
The way you are supposed to set the idle is with all accessories off, engine warm, and iacv plug off, then set to 420rpm via the adjustment screw. Turn off ignition, reset ecu for 10+ seconds, then enjoy a solid 600rpm idle.</TD></TR></TABLE>

Good luck with that.

the.hamburglar

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HiProfile &raquo;</TD></TR><TR><TD CLASS="quote">

Thats the most common problem. For example, even a small leak in your bov's diaphram will allow enough air to make it surge. To give you an idea, a .5mm gap around the throttle plate will make it surge, as happened when I tried an oem 60mm plate in a tb I bored to 60.5mm.

The way you are supposed to set the idle is with all accessories off, engine warm, and iacv plug off, then set to 420rpm via the adjustment screw. Turn off ignition, reset ecu for 10+ seconds, then enjoy a solid 600rpm idle.</TD></TR></TABLE>

ok ill try that too. but i want a 750 idle so ill unplug the iacv and set that to 500 for a 750 idle?

EE_Chris

Is it really that hard for you to believe that the base map you're using isn't going to produce a 750rpm idle right from the start? That it actually does need to be tuned?

SovXietday

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Joseph Davis &raquo;</TD></TR><TR><TD CLASS="quote">

Good luck with that. </TD></TR></TABLE>

X2, lol.

the.hamburglar

idle is set at 750 on the map so yes once it stops surging i belive it will settle down to that. on a cold start it runs great with an idle of 750 but once i start moving and then come to a stop again the idle gets all messed up. imjust trying to narrow it down. i think its a small possibilty its the map but i know there has to be other things affecting it

Turbo-LS

iTrader: (4)

More the nlikely its teh base map, when not tuned properly its going to idle surge if all other issues are solved liek air bleed the cooling system. The reason being is its going to keep going rich lean rich lean around the idle area which will cause the idle to hop up and down. Best bet is get it tuned. Reason there called base maps is to have a bsae to start with on the tune not to load it up and boost around .

Joseph Davis

Yeah, like the obvious reality that the map is for a car that has "other things" going on that are different from your "other things." Seriously, screw the small possibilities.

You need to reset TB and TPS via factory recommendations... it's not going to work out at all like HiProfile says if you are running any low-Z injectors with more latency than DSM 450cc, and you might have a problem getting the engine to maintain a sub 650-750 rpm idle even with the high-Z RCs.

Then you go and tune the map. Target idle in Crome is useless, if that is what you are going by, it's a pretty box that does nothing, and even in the other flavors of Honduh softwares it doesn't mean a whole hell of a lot. The recent 1.2.5 Beta release with actual real honest to god IACV duty control will allow you to set your idle as low as possible, which might not be as low as you want it to go if the throttlestop has the throttleblade cracked too far open, or your air bleed screw is out too far.

You can dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick around all day long fooling with **** that doesn't matter, or blindly yamming on things with no understanding of the system's dynamics, or you can follow my simple instructions and get the job done. I could have tuned your idle and be most the way through driveability with the time I have invested into the posts in this thread trying to steer you right. I do this stuff all the time, and I like to think I'm good at it. Please, stop fiddling around with non-essential stuff and just take care of the problem.

PS - the high idle from a roll stuff can be found via Crome's Advanced Tables, so Ctrl+L your way to happiness. If you want a short cut to keep said high moving idle from mussing your idle at a standstill you can turn it down - target idle actually works there.

SovXietday

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Joseph Davis &raquo;</TD></TR><TR><TD CLASS="quote">
You can dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick dick around all day long fooling with **** that doesn't matter, or blindly yamming on things with no understanding of the system's dynamics, or you can follow my simple instructions and get the job done. </TD></TR></TABLE>

/Thread.

That new IACV duty cycle on the crome beta works wonders.

Joseph Davis

Yah, I like it. I like it a lot.