spluttering @ 4000rpm!!!
 

My pride and joy has just started showing sign's of ill health!, It's a 99 spec turbo with full de-cat and ITG filter, appart from that it's standard.

Recently it has developed a rather disturbing splutter when @ 4000rpm, almost as if the car is misfiring. When below or above 4000rpm the car runs fine, it only coughs when the needle is on the 4.

I have changed my air filter in the hope that the engine was beeing starved of air but, this made no differenc.

Am scratching head, Any ideas ????

I had something similar on my old Lotus Carlton - ran fine till about 3.5K revs and started spluttering. That instance turned out to be HT leads. I'd check them and the spark plugs.

Hope you get it sorted out;)