the idle issue has been improved. once warm it sits at 8 or 900 and that's fine. I'm pretty sure mybac is doing nothing so that'll need replacing. new problem after I set all the tb adjustment where it should be is it surges from 1500 - 2500 rpm. I'm getting pretty frustrated as it's going from one problem to an even more annoying one and I haven't even been able to drive it yet.

 

does the factory ecu require info from the factory water temp sensor? I substituted mine for an aftermarket gauge and sender because I have a s4 ecu, afm, boost sensor with series 5 engine and apparently they scale differently between series so wanted accurate water temp readings.

 

The ECU gets it's water temp info from the sensor on the back of the waterpump housing, not the sending unit for the gauge.
Your gauge replacement didn't bother the ECU at all.

 

ok so I will still need the petrol to end my suffering.

 

your bouncing is caused by the TPS being out of adjustment...Unless you removed something recently on the engine,Then I would suspect a vacuum leak.

 

it's gonna need replacing. it's set at 1k ohms but it goes up to 7.5 at the end of it's range.