Haas boss Gunther Steiner says he is confident his team will be able to run unimpeded on Thursday after having been hit by problems on the opening two days of testing at Barcelona this week.
Esteban Gutierrez got just 23 laps in on Tuesday before having to stop with issues, and the Mexican driver could only completed an installation lap on Wednesday due to problems with the turbo.
After having spent the day analysing the problem with engine supplier Ferrari, Steiner is hopeful the team can have a solid day on Thursday.
"They changed the turbo last night and this morning we found an anomaly and we went out for the installation lap and realised that the turbo didn't do what it should be doing," Steiner said at the end of the day.
"So we can't say 'just change the turbo'. It needs a little bit of analysis and thinking and that was it. We had to change it again.
"We are confident. We've analysed the problem and we got it fixed, but you never know what's coming next. But I think we are good to go tomorrow."
Steiner said the team aims to complete a race simulation tomorrow, but admitted all plans are subject to the car running trouble-free.
"We have to try to do a race simulation and to get as many laps as possible to learn what the car is doing and what are the problems we have got," he added.
"So that is the main aim for tomorrow: to get as many laps in as possible and then when we see how tomorrow goes we see what we do on Friday.
"Now it's an hourly plan more than a daily plan. It could change every hour depending how we get going tomorrow."
Additional reporting by Jamie Klein