hi. im currently on with putting my s1 back on the road and im having trouble with missfiring under boost but only once warm, i know it does need a gud set up but i dont want to take it some were to be set up and end up fitting parts all day long to cure this problem first, cheers mark

 

How do you mean only when boosting when warm??? Surely you wouldnt be boosting when cold anyway??

 

ok then sorry, will boost up a few times once warm but starts missing once temps get a bit higher, would too much boost pressure cause this

 

Hi Mark i would start with basics ie plugs, leads, etc etc and make sure everything is spot on, could be the plugs breaking down once temps get high or the leads etc etc...
As for the boost what spec is the engine and what boost are you running ?
Cheers
Chris.

 

check plug gaps to boost might be blowing ot spark