do i have a bad TPS sensor ???

when my car wasnt turbo yet it does it also...

2,000 rpm cold starts and then drops to 1500 rpm most of the time
but then sometimes drop to 900 rpm after driving a while

i then check my pcv box and made sure it doesnt leak
so i put on my turbo kit. it was hard to street tune because Idle wouldnt stay the same all the time. it would idle up and down and mostly stays at 1500 rpm at normal temp
my afr would be at 14.7 at 1500 rpm and if i decrease fuel to 18.5 afr it would stay at 900 rpm
my timing is off a little when idle is at 900 rpm but when at 1500 its perfect

because i tuned it for 1500 rpm idle
boost kicks hard and no backfire or anything
10 psi of boost running off WG with no spike or creep with a 38mm TIAL

my TB is a stock GSR never tampered with. i need help so i can get an accurate tune

setup

GE b18c1 81.50mm
9-1 cr
stock head
stock gsr cams
JG intake manifold
topmount t3/t67 3 inch dp
38mm TIAL
880cc precision
stock FUEL PUMP


crome pro w/ plx wideband
latest version of crome pro tuned by my bro
we did a 5 hour street tune
very safe tune


Modified by black_ek at 1:47 AM 6/24/2008

 

Maybe an idle air control motor?

 

what he said
most likely your iacv.

it also could be a bad coolant sensor if they have the same thing in the intake mani as most fi cars do, it usualy idles at 2 when it is cold and the normal for idle when it is at running temp is 8-900 for me anyways same with my other toys.

if your car is warm and your idle is irractic it could be a bad tps sensor or iacv but i think it is more like it should be

 

i changed 5 different iacv and still the same but havent changed TPS or TB yet. i will try a different TB when i find one.

i need this to idle right so i can get an accurate tune

 

sounds like a small vacuum leak.

 

its not vacum leak because i have a 10 psi spring and it boost perfect with no leak, creep, and or spike and stays at 10 psi all the way

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by black_ek &raquo;</TD></TR><TR><TD CLASS="quote">its not vacum leak because i have a 10 psi spring and it boost perfect with no leak, creep, and or spike and stays at 10 psi all the way</TD></TR></TABLE>

You may be getting air in the coolant lines to the iacv or the gasket may be leaking. Your iacv may be trying to compensate for a vacuum leak.