A friend has a 2000 Vette that will barely idle. Car is bone stock with 30000 miles on it. Below is an Autotap recording of it at idle.
The odd thing is that the throttle position is showing 14.5% at idle. See below.
Before he spends $160 on a TPS is there any thing that I can check to verify that it is infact the TPS?

Thanks,
Blown355


Fuel System Status Bank 1: OL-1
Calculated Engine Load: 0.8 %
Engine Coolant Temperature: 86 °F
Short Term Fuel Trim Bank 1: -0.8 %
Long Term Fuel Trim Bank 1: -0.8 %
Short Term Fuel Trim Bank 2: -0.8 %
Long Term Fuel Trim Bank 2: -0.8 %
Manifold Absolute Pressure (MAP): 22.4 in Hg
Engine Speed: 930 RPM
Vehicle Speed: 0 MPH
Mass Air Flow Rate: 0.323 lb/min
Throttle Position Angle: 14.5 %

 

MAP looks too high, possibly caused by the throttle being too far open. I'd expect to see something closer to 10"Hg MAP.

Unlike the LS1 in the F-Body, the Corvette has the electronic throttle control..... no cable. The PCM controls the throttle position to handle idle speed, cruise and traction control. When you see the TP% figure on the scanner, its the "gross" position.... it will always be open because that's the idle air control, no separate circuit. 14.5% seems like a large number. The electronic throttle in my Silverado is generally around 5-6% at idle. But it doesn't necessarily mean the TPS is faulty, it may just mean some other problem is forcing the PCM to open the blades to keep the idle up. I don't know what the stock idle speed is on the 'vette, but 930rpm looks high.

 

Fuel System Status Bank 1: OL-1
Engine Coolant Temperature: 86 °F

The idle speed is high because the engine is cold and in open loop. Post a log with it fully warmed up.
Also, SES light on?
Fuel, air filters ever been changed?
Plugs?

 

I cleared the codes and this is the codes and freeze frame data. I have also changed the plugs,plug wires, and #6 coil. I also check the "Throttle Position Angle" again with key on but engine not running. The "Throttle Position Angle" never went below 15.8%. When the car is running (very rough) the car is running very rich.

with car not running but key on.
gas pedal not pushed Throttle Position Angle: 15.8%
WOT Throttle Position Angle: 99.6%


AutoTap Diagnostic - Version 3.00
Date: 9/9/2006 8:59:23 AM
Hardware Serial: 0061920025

Check Engine Light: ON

Time Since Codes Cleared: ---
Distance Since Codes Cleared: ---
Drive Cycles Since Codes Cleared: ---

Confirmed Diagnostic Trouble Codes:
Code: Description:
P0300 Random/Multiple Cylinder Misfire Detected
P0306 Cylinder 6 Misfire Detected

Possible Diagnostic Trouble Codes:
Code: Description:
P0306 Cylinder 6 Misfire Detected

--------: EMISSION TEST STATUS :--------
Emission Status: Fail
Vehicle Model Year: <SELECT>

OBD Compliant: Yes
Misfire Monitoring: Complete
Heated Catalyst Monitoring: Not Supported
Comprehensive Component Monitoring: Complete
Catalyst Monitoring: Not Complete
Fuel System Monitoring: Complete
Evaporative System Monitoring: Not Complete
Secondary Air System Monitoring: Not Complete
EGR System Monitoring: Not Supported
Oxygen Sensor Monitoring: Not Complete
Oxygen Sensor Heater Monitoring: Not Complete
A/C System Refrigerant Monitoring: Not Supported

--------: FREEZE FRAME DATA :--------
Generated by DTC code: P0306

Fuel System Status Bank 1: OL-1
Calculated Engine Load: 3.9 %
Engine Coolant Temperature: 91 °F
Short Term Fuel Trim Bank 1: -0.8 %
Long Term Fuel Trim Bank 1: -0.8 %
Short Term Fuel Trim Bank 2: -0.8 %
Long Term Fuel Trim Bank 2: -0.8 %
Manifold Absolute Pressure (MAP): 28.6 in Hg
Engine Speed: 755 RPM
Vehicle Speed: 0 MPH
Mass Air Flow Rate: 1.503 lb/min
Throttle Position Angle: 16.1 %