Apr.8 (GMM) The Renault cars did not immediately run in Friday afternoon practice while the team investigated the technical failures of the initial session at Sepang.
Team boss Eric Boullier confirmed at the Malaysian circuit that neither Nick Heidfeld or Vitaly Petrov would return to their R31s until the problem is understood and rectified.
"Best to be on the safe side," the team said on its official Twitter.
Heidfeld had returned to the pits in the first session with a blocked wheel, before Petrov spun into the gravel after a catastrophic failure on his left corner.
It was initially believed the problem was related to brakes, but the later theory was that the fault was in the suspension upright.
Half-way into the second session, it is believed the problem has been found and the cars will return to the track shortly.
Meanwhile, Boullier confirmed that German Heidfeld sat out some pre-weekend events this week with a throat infection.
"It's not serious," he told Bernama news agency. "He wanted to rest and be ready for free practice."
