18-07-14, 05:07 PM
I recently when thru something similar, and it turned out to be a clogged up air filter. Here's the thread with some solid sensible advice from Unfazed and others here.
http://foc-u.co.uk/index.php/topic,13563.0.html
http://foc-u.co.uk/index.php/topic,13563.0.html