McLaren and Fernando Alonso's opening day of running at Indianapolis was thwarted by an electrical issue that denied the Spaniard crucial practice mileage on Tuesday afternoon.
Alonso ran 50 laps at the start of the day devoted to his "Refresher Test" but McLaren's Chevrolet-powered contender was sent back to Gasoline Alley after just a single lap in the afternoon session, restricted from running by a strange electrical issue that confounded McLaren's Gil de Ferran.
"I think the plan here was to run more than we did," de Ferran told NBC Sports.com.
"Obviously, I’m disappointed and a little frustrated we had the issue in the afternoon. We are trying our best to understand what the problem is. So far, it’s baffling. We lost the entire afternoon session.
"This morning was a bit of a warmup. He still needed to do a bit of a run to complete his refresher with a conservative setup on the car.
"Not running this afternoon really hurts us. Here in Indy, when the weather is good, you want to be out there, and today was a day of good weather.
"We have a lot of capable guys. We will get on top of this matter and see."
McLaren planned to replace the entire wiring loom on the engine in a bid to solve the problem.
After partnering with Andretti Autosport two years ago for Alonso's maiden run at Indy, McLaren is at the Brickyard on its own this time, although it enjoys a small alliance with Carlin for the event.
"We are under no illusions how big a challenge we have," de Ferran admitted.
"We have a lot of experienced people in the group, but we haven’t run together as a team ourselves everyone together before. Any help that we can get is better than no help.
"There are some really talented guys, but we have a lot of work ahead of us.
"I don’t think of those expectations. Even when I was a driver, I’d look at the situation I’m in, try to understand the weaknesses and opportunities we have and tackle them head-on.
"If you do that in a consistent basis every day and successfully, usually the results will come.
"Hopefully, we’ll get on top of some of the issues we have today and get a fresh start and clean run on Wednesday," added the 2003 Indy 500 winner.
"We need to review what we are going to do now. We lost three hours this afternoon. We have to develop the setup. We haven’t discussed exactly how we want to do the day on Wednesday."