F0RSAKEN

This is more for other peoples benefit than my own, because in my searches I found 100's of "omg my idle is bad help!11!" and "bucking/bad idle/surging/dieing" etc....and most of them never being fixed or at least stating they had figured the problem out.

This is directed more toward single turbo/non-seq/PFC people, because generally those people dont have the AWS/ISC, which can effect how the vehicle is diagnosed.

Here Ill list the symptoms, so It will show up in a search:

Bucking
Surging
Searching Idle
Hesitating
Slowly dieing from idle

I started out just like every n00b here, and posted an oblique thread trying to figure out my problem, because I think best when all my questions are already asked.

I read probably dozens of threads dealing with idle something or other, and had already read damian's thread when he had posted it. After retrieving it, I checked the voltages of the 2 wires on the TPS, and both were off a bit so I performed the TPS adjustment. After that didnt fully cure my problem, I moved on to my own troubleshooting.

One thing to note when starting with the TPS adjustment: there are TWO screws you have to set to ground zero on the TB, one vertical, and another that sits right next to it horizontally. They both do the same thing as far as I can tell, but for different throttle butterflies.

After I did the above, my idle actually got worse and I had a hard time getting the real adjustment screw (under TB) to have any effect. After checking everything else (ignition/vac) I decided it had to be a sensor.

Sitting in the car with it running choppy, I started with the voltage readout screen on the PFC, noticed that the O2 was sitting at a steady value (4.98v), and realized right off that it was incorrect, so I turned it off to let the computer run the car without its input. Viola, perfect steady idle.

So a bad O2 added to incorrectly set TPS ended up being my problem.

If this thread is deemed useless/old news, please delete so it isnt cluttering forum space.