Screw loose

[JumboBeef]

A previous owner of my 400 told me that, for MOT time to get the emissions right, there were "a couple of screws on the side (of the engine/EFI???) that were turned. If these are turned back, you'll get more power".

I don't have any idea about what/where these screws are and indeed how much to turn them or which way.....

Can anyone enlighten me please?

[ElvisWedgely]

I would not turn any screws on the side of the engine or the efi without the use of specialist equipment and extensive knowledge of tuning engines. If you have any doubts, get it professionally tuned to the correct emissions and settings. It should then stay that way, pass the mot, and have ample power.

Tony.TCB.

[adam quantrill]

Yeah you need a CO meter to do it right. The only one of interest is the idle CO which is governed by the bypass screw on the air meter. You could dial it up to 2.5% CO which is still legal.

It won't really make a huge amount of difference, maybe very slightly less hesitation at low revs, and at high revs no difference.

The other thing to adjust is the idle speed, turn it down if it was turned up for the MOT and you want to save slightly on petrol usage.

[Wedg1e]

Some ECUs have added pots for twiddling. Often marked R and W (for rich and weak ).

[JumboBeef]

Cheers.

Are this thread and this one http://www.pistonheads.com/xforums/topic.asp?h=0&a... talking about the same thing?

[adam quantrill]

Yep!