kobraa

iTrader: (1)

I have been having this same idle issue ever since my rebuild on my 98 Trans Am. I have full bolt on's, TSP 233/239 cam, TSP 3" Dual exhaust, and FAST 92/92 setup. I got it tuned over a year ago by RPM in Delaware but have recently had stupid idling issues. I just changed my fuel pump and filter, got a replacement 98 engine harness, new MAF sensor, new IAC sensor in the throttle body, and I have checked for vacuum leaks everywhere. I HAVE DONE EVERYTHING I CAN THINK OF but this issue never seems to go away!! My check engine light is also on. Here is a video of what it sounds like. Does anybody have any ideas? What else can I be missing??

zacht

iTrader: (18)

says the video is private...?

kobraa

iTrader: (1)

I just changed it, should be able to view it now

zacht

iTrader: (18)

mine does a little bit of that too...but only in open loop mode...once it warms up and goes closed loop it idles fine....

i have hptuners...but really dont know how to solve it...my cam is about the same 231/239 lsr cam...after about 30 seconds it goes away...

im in for some advice too!!!

lemons12

iTrader: (71)

What is the code?

Hole drilled in tb?

kobraa

iTrader: (1)

I'm going to autozone soon to figure out the codes. You think it has something to do with my stock 02 sensors? They have about 120k on them. My throttle body doesn't have any drilled holes in it..

old93camaro

iTrader: (8)

your TB blades need to be opened its staving for air, after you open it a little then reset the TPS

old93camaro

iTrader: (8)

let it get to operating temps and then check your IAC counts and make sure its not over 100 ( for me mine is at or around 60- 70 and i have a bigger cam)

kobraa

iTrader: (1)

Alright how would I reset the TPS?

old93camaro

iTrader: (8)

first do you have a multimeter to measure volts with key-on engine off? if you do you need a range within .05-.06 and at wot less than 4.75. then you would need a scan tool to see the % of the tps with car running. Its a write up some where telling you how to do it step by step.

kobraa

iTrader: (1)

Anybody else having symtomes like this? I really need to fix this issue

A3sch 98

If it did it a little more rapidly and didn't jump through such a wide range on the tach, it would sound pretty badass like it had a blower or something but Yea that sounds like a throttle body issue... I think the computer is trying to compensate for the lack of air so it lowers the fuel injection rate, and when it finally gets enough air, it spits in the fuel and thats when you get your jump... TB issue!

old93camaro

iTrader: (8)

crank that blade kobraa lol , for real follow those steps i talked about if you have the right equipment and it will improve but it will be slowly. it takes the longest for the computer to learn the idle for some reason.

Zzzzz

iTrader: (2)

My H/C 98 did (or does) the same thing. I worked with a tuner via email, but we didn't seem to make much progress on it.

I noticed that the stft's would just creep higher and higher, max out, and that's when the idle would start acting the way yours does. My short term fix was to force it in OL below 1600 RPM. That bandaid fix has worked enough for the car to be pretty well behaved for the time being. I haven't had time to figure out a proper fix, so for now, that's how it sits.

Does anyone have any non-throttle-blade possible causes? I couldn't get any amount of throttle blade adjustment/IAC tweaking to get it in line.

old93camaro

iTrader: (8)

zzzzzz if its not in the tune or the TB then you have a leak some where that's letting air in. remember learning idle is the longest process of the PCM .

Zzzzz

iTrader: (2)

I can't figure out where if that's the case. I retorqued the fast intake and triple checked everything by the tb. What could I be missing here?

old93camaro

iTrader: (8)

if you have some carb cleaner laying around i would spray that around the area to find it

BuffJoeyD

iTrader: (2)

Its pretty simple to dial in the IAC / TB to get a situation like this to go away. Seen far too often an owner state over and over that there are no leaks when there still was some small leaks hidin =)