2G Idle air control code VS wastegate

[Xsvpaintball]

Hey everyone!
So I have 2 codes reading. It I think they might be related. I have the idle air control code and the wastegate actuator circuit code. Not sure if one is caused by the other. Here are my symptoms:

1.bad surging
2.High idle
3.When letting of the gas on the high the car kinda shutters and my air/fuel ratio bounces to rich
4. Bad fuel economy

I did just redo the intercooler piping and a new recirculating valve. Everything seems clamped good and hoses all look connected. I did have the idle air control valve replaced back in august.

Any input would be amazing! Thanks!!

 

[steve]

Do you still have the ISC/IAC and BCS (wastegate solenoid) installed?
Can you measure the resistance of the coils in each. The ISC/IAC has four coils and BCS has one.
Why did you replace the ISC/IAC back in August? Where it's coils shorted. What did you replace it with?

The common point that I know of for these faults are shorting out the drivers in the ECU. That can be caused by a bad solenoid, by water in the connectors if they are hanging loose, or by pinching the wiring harness.

Would you please fill out a profile so it's obvious to everyone what car you're talking about when they read your questions. I'm assuming these are for your 99 GST Spyder.

 

[Xsvpaintball]

Yes, I have the solenoid installed. It may just be old. I replaced the Idle Air Control Valve because of the surging thinking that may fix it. I’m thinking I could just replaced the solenoid and be good. And yes this is the GS-T

 

[Hickory-NC-2Ggsx]

Check your tps sensor, I've had bad ones cause the surging and bad fuel economy.

 

[Xsvpaintball]

Check your tps sensor, I've had bad ones cause the surging and bad fuel economy.

What’s the best way to check it? Anything I should be looking for?

 

[Hickory-NC-2Ggsx]

I just unplug it and start the car again to see if it stops surging. Or get a basic code reader to see what the tps volts are.

 

[Xsvpaintball]

I just unplug it and start the car again to see if it stops surging. Or get a basic code reader to see what the tps volts are.

I have a reader so I’ll start there. What should it be at volts wise?

 

[Hickory-NC-2Ggsx]

If I remember .63 closed and 5.0 wot.