hi all i am in need of some help with an issue on a s2 Here goes
The car will start and run fine from cold then once hot it looses power and starts to black smoke from exhaust Having had a quick poke round i have found if you un plug the black box on the right hand side of the meetering head the miss fire goes as does the smoke and drives fine plug it back in again and fault returns let it cool down and its all good again untill it gets hot any ideas as to what is causing this fault
Thanks in advance lee

 

That's the EMFPA, it controls your fuel pressure and is what gets adjusted on a setup... They often drift out and it sounds like yours needs adjusting.

 

it sounds as if your box is thinking your on boost when not and giving you the required fuel for it but as your not it's overfuelling giving the black smoke time for a set up

 

Coolant sensor on inlet manifold