A2 1.4 AUA not running

[cnixon]

Hello,
Just posting to see if anyone has any ideas what may be up with my poor car.... Car lost power at speed. Would not start - recovered home. Started once and ran fine but died again after about 1 min. So that ruled out the catastrophic (cam belt jumped teeth etc.) Dash showed CEL and EPC warnings. Diagnostic was inconclusive few interesting errors 17550/P1142 not seen before - Load Calculation Cross Check Lower limit exceeded and 17961/P1553 - Barometric/Manifold Pressure Signals - Implausible Correlation. Central Conv. also had a 01366 Opened due to crash signal which got me thinking something had tripped. I have no dates for these errors so they could have been lurking for a while.

I removed the Crank sensor on a whim as soon as the car was home ...and then put it back not on a whim (what a pig) as the errors appeared unhelpful I tried to do my research online and then dropped into old school diagnostic mode (if there are no errors its probably mechanical). Ultimately I ruled out several possibilities which lead me to think that the throttle body was at fault (basically not opening). I had done an adaptation which was OK so thought this was OK but on inspection I found it was staying closed except during the adaptation process, (with the ignition on should it open in response to pedal action?) oddly it seemed to make noises even when the butterfly was not moving and the butterfly did not appear to come perfectly to the vertical, but it did its stuff and passed the test. Fuel is OK injectors are working and spark is healthy. VCDS shows EPC movement detected but I may be being fooled.

I placed a wire as a spacer to open the butterfly a mm or so (40 thou.) and she fired up but would only try to idle.

Am I stirring any thoughts?

Thanks in advance, Craig.

[Radio89]

WARNING: Moving the butterfly with the key ON can damage the motor. You can move it any way you like with the key OFF.

When performing the throttle body alignment, or even just on the adaption setting and moving the pedal manually, does the throttle position sensor value change fairly smoothly? There's often 2 sensors, one will increase at the same rate the other is decreasing. Yes the butterfly should move with the key ON and moving the pedal.

Have you removed the throttle body and cleaned it? The butterfly can get stuck on bits of carbon build up and grime. I would certainly give it a good clean just for good measure and good maintenance.

Might be an idea (Or a shot in the dark) to check the connector plug for corrosion.

If all seems well after the above we can start looking at other potential gremlins.

J

[cnixon]

My throttle position sensor appears to have two resistors (the measuring block labels do not reflect the SSP247 description which is G79/G185 so something is incorrect). Both resistors/potentiometers (VCDS calls them G79 and resistor 2 in Pedal go up together to 100% in. My confusion is why the Throttle Body adapts OK and the pedal appears OK but the throttle body (butterfly) does not move in response to pedal.

Craig