[MineralGreyGT]

Hey, I recently started to notice after a bit of driving my car idles pretty ruff it tries to stay at 700 rpms but drops every second or so to 500 it almost feels like its going to stall, here is what I have done so far to try and fix it, new coil packs and plugs, carb cleaner for the IAC, cleaned the MAI, I put back the original IAC gasket, took off MAI screen, Unplugged the battery for 5-7mins, but no results the only conclusion I have left is a vacuum leak but I can't seem to find one. any advice is appriciated!

[02MODGT]

If you can't find the leak then replace the IAC.

[Trick Tuners]

Did you install a new tune, or any aftermarket parts or did the issue just pop up?

[workinprogress]

start tracking vac lines, there is alot to keep track of around the trottle body on these cars, one may be dry and cracked, or just loose

[MineralGreyGT]

i installed new tune new tb and plenum like 4 or 5 months ago, just showed up out of nowhere. The IAC looked fine the car only has 59K miles. I'm going to try and back track the vac lines.

[MineralGreyGT]

anyone thinks it might be the TPS? if so where can I find the TPS? considering I have a 75mm TB and plenum?

[ma67cpe]

Originally Posted by MineralGreyGT anyone thinks it might be the TPS? if so where can I find the TPS? considering I have a 75mm TB and plenum?

When my car had around 60 on it it was doing the same thing. I just replaced the throttle and the tps for about 70 bucks.

It should be a factory TPS. At least it is on my acufab TB

[Trick Tuners]

Its not the TPS. Do you have a datalogger?

[MineralGreyGT]

Originally Posted by Jgorm Its not the TPS. Do you have a datalogger?

closest thing i have is the diablo tuner and the only codes im getting are the normal ones when u install a tuner. It sucks that its been really cold lately, I'm going to attack all that tommorow morning.

[Trick Tuners]

You can datalog with the diablo tuner. Shoot me a datalog with maf counts, rpm, stft, ltft, tp, pressure drop across injectors, and IAC duty cycle.

[MineralGreyGT]

Originally Posted by Jgorm You can datalog with the diablo tuner. Shoot me a datalog with maf counts, rpm, stft, ltft, tp, pressure drop across injectors, and IAC duty cycle.

alrite, I'll try and get that on here later on tonight when I get home from work, thanks for the help.

[MineralGreyGT]

all rite here goes I'm not sure if I got everything but here is what I got
MAF V 0.4v
rpm 0
STFT1 -25%
STFT2 -25% <-- there was no LTFT
FRP 39psi
TP 0.88v
74F IAT

The second time I did it
56F IAT
o RPM
0.4v MAF V
37psi FRP
10deg spark advance
70.9% load
open feed back fuel
92F Eng coolant
STRT1 -22%
STRT2 -22%
TP 0.81v

Thats pretty much the same data I got on the different options I chose I've never used data logging before. The car stays off correct? thats what I did anyway well thanks again for the help.

[00vabchgt]

it could be the TPS, i had a probalem with mine, but i had a code coming up. try cleaning the IAC and check for a vacuum leak...

[limited]

Originally Posted by MineralGreyGT all rite here goes I'm not sure if I got everything but here is what I got MAF V 0.4v rpm 0 STFT1 -25% STFT2 -25% <-- there was no LTFT FRP 39psi TP 0.88v 74F IAT The second time I did it 56F IAT o RPM 0.4v MAF V 37psi FRP 10deg spark advance 70.9% load open feed back fuel 92F Eng coolant STRT1 -22% STRT2 -22% TP 0.81v Thats pretty much the same data I got on the different options I chose I've never used data logging before. The car stays off correct? thats what I did anyway well thanks again for the help.

not sure,but think he will want data with rpm and at normal operating temp

[HMUSN]

^ +1

go do a 3rd and 4th gear pull while data logging

[Trick Tuners]

No need for more data. Its either a vacuum leak or a bad tune. Did the tuner customize the tune based on your data? 25% is as far as the computer can correct fueling and its pegged so who knows how bad it really is. You should not go WOT till you get this figured out.

[MineralGreyGT]

that is the tune that cam with the programmer, all I did was advance the spark timing I'll try to reinstall the factory tune then reinstall the normal tune. I aslo noticed where the hose clamps on the throttle body is loose I overtightened it and I broke the clamp but it seemed nice and sturdy when I was done I guess from all the removing and installing it got loose. I'm going to get new hose clamps and try to replace the dried out hose connections.

[limited]

you need to datalog with the car running,both those log's the car is not.

[MineralGreyGT]

well I found out that the diablo tune is all f'd up its running really lean even if i reset all the parameters it runs to lean, but it runs fine with the stock tune so I'm going to have to have it dyno tuned, o well atleast I'll know what I'm putting down at the wheels thanks for the help guys much appriciated!

[MineralGreyGT]

head ache grows worse now it wont calibrate the speedo towards my 4.10 gears wtf!?!?