Check the IQ valve under the seat. It is usually the problem when street racing a stock car.
07 335XI (A008006) 6AT ~94K miles JB4 G5 ISO VSRF DP's
09 135I M (VK80379) 6MT. Race Project car. 1) Install Cobb/piggyback? and Motiv 600 Kit[HTA3076R w/ tial .82] 2) JRZ or Moton suspension. 3) Build high flow intake manifold with multi-port fuel and relocate OFH 4) Build full cage 5) Complete staged twin setup with HTA4205R [w/Tial 1.16] 6) Complete dry sump system