Idling issues

[Ben182]

Howzit

Have an idling issue with my Golf 1, it idles properly in the morning but after a couple of drives it starts this erratic idle, almost switching off everytime I come to a stand still or turn. Have tried to reset the ECU by disconnecting the battery over night but it's not improving. Any thoughts on what could be wrong?

Diagnostics scan picked up: throttle body Correlation issue.... If that was the issue would it not be consistent even in the mornings?

[panic-mechanic]

Assuming citi golf. Which year. Ie. mp9 or mpi.
throttle body calibration might help.
Disconnecting that battery does not fix squat on anything.

[Ben182]

Yes it's MP9, is throttle body calibration the same as throttle adaptation- if it is I did that today and it has improved slightly. These are the codes it's throwing:

03840 - RPM Sensor Front Right: Incorrect Signal
07-00 Signal too low.


Address 25: Immobilizer

2 Faults Found:
01176 - Key
07-00 - Signal too low

00546 - Data wiring faulty
27-00 - Implausible Signal.

Have changed the throttle body and MAP sensor, starting to think it might be a faulty wiring or my immobilizer is stuffing up the system. Not sure if it has any effect on idling etc.

[panic-mechanic]

If the immobilizer didn't work either the car would not run at all or there is a decoded box installed.
If the adaption did not help then change the thotlle body and try again.

[Ben182]

Hi thanks for all the info, so I installed an old throttle body I have and the erratic idle is on/off. The whole thing is baffling. Had an issue with the wiring harness some time ago (connects, throttle body, injectors and map sensor) - one of the injectors wasn't firing. I think it's a wiring issue looking for a good auto electrician who can check that for me?.