Wavery idle and black smelly smoke when stationary - help please?

[Guest TwinTurboJoe]

I've just put my Supra back on the road after a couple of months being SORN'd and after a long run in it this morning it is driving ok again and the power is still fine but when the car is stationary in drive, neutral or park (it's an automatic) the idle completely goes, wavering up and down and the exhaust starts to kick out black, smelly smoke. I have never had this before. Any ideas on what the problem could be would me massively appreciated, Thanks.

 

The car is a J-spec '94 reg twin turbo.

[JustGav]

Check your boost pipes?

[Ian C]

It's overfuelling loads. You may have popped the hose off the MAP sensor, which means it's fuelling for atmospheric when it should be fuelling for a high vacuum. This would also mean it would only fuel for atmospheric when on boost, which can destroy your engine - so make sure you check it before giving it a thrape.

 

Failing that, check the output from the lambda sensor. Details on how to do this are in the FAQ section