Jakes' times were deleted for triggering the red flag, but the British driver said that he hoped the team could find the problem in time to allow him to see what he can do from the back row of the grid: "We were working on the Acorn Stairlifts car all day and made some improvements before qualifying but we went out to make a run and had a problem with the engine," he explained.
"We're not quite sure what it is right now but we will identify it and try to come up with a solution," he added. "If we have a good car we will be able to pass and there are a few places to pass on this track so that should help but this is obviously not ideal."
The other round 1 group was also interrupted by a red flag, but this one was slightly more conveniently timed for the end of the ten-minute session and was caused by Tristan Vautier bouncing over the kerbs through turn 1 and clipping the tyre wall in turn 2. It made for the third session in a row that had seen the Frenchman have an accident of varying degrees, but he insisted that he was enjoying his first visit to Sao Paulo nonetheless.
"I really enjoyed the first practice," he said. "It's very slippery and there's a lot of fighting behind the wheel. It was fun, it was a lot of work and very hard to attack and not make mistakes."
Vautier is the only driver in today's field not to have races on the Sao Paulo street circuit before, but everyone is having to relearn the first part of the circuit after organisers remodelled turns 1 and 2 to reduce the kerbing and allow more room through the opening corners, in a bit to increase overtaking opportunities during the race which instead had resulted in a number of incidents on Saturday.
The track modifications were assessed as taking three quarters of a second off the overall lap time, and Hunter-Reay's pole position lap of 1:20.4312s (113.508mph) - three tenths ahead of Viso - was 0.8406s that Will Power's 2012 track record of 1:21.2718s that the Australian set in in a rather happier qualifying session 12 months ago.
Sunday's race starts at 11.30am EST (16.30pm BST) and is preceded by a short 30-minute warm-up session in the morning at 7am (Noon BST).
Practice 1 times
| Practice 2 times
| Qualifying times and starting grid