Engine 94 gt 5.0 sporadic idle issues

[Ashmann70]

I NEED HELP!!!
I've had my 94 gt for three years. was bone stock when I got it. Now it has a few mods...
tfs1 cam
gt40 heads with upgraded valve springs
alluminum roller rockers
24lb injectors
X pipe with flowmasters
BBK cold air
tf track heat upper and lower intake
proform 75mm tb
sct chip with tune
3:55 gear
and engine has around 2500 miles on a complete rebuild.
The car runs strong, but will surge and die at idle ALOT! It is getting really frustrating! I love the car but I'm begining to think there is no cure! Any of you had these issues? How did you fix it?
I should say that I have not had it tuned since i installed the intake and throttle body. I also think maybe this pro form tb is junk!!
It had these same idle issues before i put on the intake and tb.

 

[General karthief]

Ashmann70: first thing you need to do is check for vacuum leaks, there is a thread in the tech/how to forum called 'the surging idle checklist'. It may help you from wasting money and time,

1TDUBB1: your dealing with a carb, so your problem will require a different process but you likely also have a vacuum leak and/or a mis adjusted carb.

 

[jozsefsz]

You put on a brand new TB so you'll have to adjust the idle air bleed and / or the idle stop to eliminate surging, following the advice posted above to use the checklist which walks you through all those steps in detail.

 

[VibrantRedGT]

Plus the TPS must be set to .98v on the throttle body or it will surge like crazy.

Sucks that you cannot just swap the stock throttle body sensors over to a new throttle body without adjustments.

The TPS is very sensitive, I had to drill the metal rings out on mine in order to achieve .98v but once set the idle was rock solid.

 

[jozsefsz]

The TPS thing doesn't apply to the SN95. Anywhere between about 0.9 and 1.1 and the computer is a happy camper - it uses the startup voltage value as the baseline for idle. Anything outside those bounds and you'll throw a CEL.