alright, i've been scratching my head about this for a few days and thought i'd ask for some help. i have a 99 gs-r and it's got a fully built all motor set up. 199.6whp. it is a fairly low compression street driven motor(11:1). after it warms up the idle fluctuates between 300-750 up and down almost as if it were a vacuum leak. but there is no vacuum leak. has anyone ever had this problem and if so, how'd you fix it. i'm runnin an msd 6al, ngk plugs, magnecore 10mm wires. thanks.

 

it might be just because you have high profile cams? other things to look at are the fitv and iacv.

 

i know it's not the cams. i've been driving on this motor for 1-1/2 years and this problem just started. my iacv is fairly new also. could it maybe be my coil or plug wires?

 

same problem, same question, never gotten an answer that worked, good luck
the only thing i also have is msd - what are the chances that could mess w/ idle

 

just noticed a bunch of corrosion on my coil wire terminal. i'll try cleaning it off tonight and see if that helps.

 

also same problem and same question on built all motor ls with msd ignition and blaster coil-still have no clue what could be causing it

 

FITV?IACV?

 

similar thing happened to me, turned out to be my intake manifold gasket. The leak was so bad, if I put hand over the intake and starved air, the car still ran.

 

yea - i dont know about the other guys, but if its a vacuum leak id be shocked - i also tried taking of my filter and putting my hand over the end and i seriously thought it was going to suck my hand in until the motor died, so like i said ive pretty much ruled out vacuum
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by greaseball &raquo;</TD></TR><TR><TD CLASS="quote"> i'm runnin an msd 6al</TD></TR></TABLE><TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by frenchy &raquo;</TD></TR><TR><TD CLASS="quote"> i also have is msd - what are the chances that could mess w/ idle</TD></TR></TABLE><TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 94SHOWLS &raquo;</TD></TR><TR><TD CLASS="quote">also same problem and same question on built all motor ls with msd ignition and blaster coil-still have no clue what could be causing it</TD></TR></TABLE>
coincidence?

 

Injector Seals, IM Gasket, TPS, or air in the coolant. I would look into the injector seals, because thats what my idle problem was.

 

I also have the msd, no idle fluctuation.

 

injector seals? - wouldnt you leak gas? - at least its a new suggestion - you just replaced the two o-rings(cant remember the name)

 

https://honda-tech.com/zerothread?id=817653

https://honda-tech.com/zerothread?id=809571

https://honda-tech.com/zerothread?id=777553

 

I wrote this in the thread that tilt just posted...It's probably your FITV (fast idle thermo valve)located under the TB...take off the 3 10mm bolts, then the 2 8mm bolts that holds the plate on, then screw in the odd-looking white thing...take 2 flathead screwdrivers to do this...that acts as a vacuum leak, and probably your problem.

if not, check out the other link he posted

 

thaks for the links - ive got a str tb w/ no fitv so i guess im still screwed

 

also thanks for the links, but i'm runnin a type-r tb. no fitv. i guess i'm screwed also

 

ok now my problem is i have a low *** idle. when the car fully warms up it drops to 1-200. im afraid of it dying sometimes. what could this one be?

 

adjust the idle

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Fullthrottlegsr &raquo;</TD></TR><TR><TD CLASS="quote">ok now my problem is i have a low *** idle. when the car fully warms up it drops to 1-200. im afraid of it dying sometimes. what could this one be?</TD></TR></TABLE>