I've searched through many threads and found nothing that has helped me.

What the car is doing:
If I crank the car up and sit still it idles like a champ ~1000rpm on the stock tach. I know thats off, but it's just there for reference. The problem comes up when I come to a red light a few hundred feet away. I put the car in neutral and coast and the motor drops to ~400rpm then quickly jumps to ~12-1300rpm then stalls, repeatedly. Then after I come to a stop I crank the car up and it idles fine at ~1000rpm again.

What I've replaced:
IAC
TPS
O2 sensors(both)

This drives me absolutely crazy. I've replaced those sensors that I thought could be the problem and still nothing does any good. The car only does it on DECELERATION. Any help would be GREATLY appreciated.

Wade

 

Im no pro, but could be a torque converter considering it only does it in neutral.

 

Should've clarified I guess. It's a 6-speed with an LT4 hotcam kit, all the bolt-on's, Hooker LT's, Mufflex exhaust, etc...

 

Have you had the car tuned? If not you are probally needing of a good computer chip.

 

Yes, it had a mail order tune from you guys I think before I got the car. Then I got it retuned by a local guy after I put nitrous on the car.

 

You might want to check to see if the TB blades are open enough. Sometimes you can close hem off to keep the IAC out of a normal working range. Warm IAC counts at idle should be 20-30

 

I have no way of checking IAC counts.

Would the sticking TB blades only happen on deceleration? I can rev it up all day long while the car is sitting and it comes back down to normal.

 

Tuned before or after the cam?

 

All the mods have been on the car for several years now. It was recently retuned(about 3 months ago) and I've always had an idle problem since I got the car in Nov '04.