A day after ousting two top executives, the electric truck start-up Lordstown Motors said on Tuesday that it was on track to start production in September even if it does not raise additional funding, contradicting what it told securities regulators just a week ago.

In a filing to the Securities and Exchange Commission last week, Lordstown said it needed to raise more money and might not survive. Then, on Monday its founder and chief executive, Steve Burns, and the company’s chief financial officer resigned.

But in a news conference hosted by the Detroit-based Automotive Press Association, the company’s new executive team presented a far more optimistic outlook without providing many details.

Lordstown’s president, Rich Schmidt, said that the company would start making trucks at its plant in Lordstown, Ohio, in late September and that it had enough money to last until May 2022. He said the company would be able to make about 15,000 trucks over the next 24 months.

He also said the company was still actively seeking new funding to increase production.

“It’s a new day at Lordstown Motors, and there is no and will be no disruption to our plans to start production,” the company’s new executive chairwoman, Angela Strand, said. She had previously served as the lead independent director on Lordstown’s board.

Lordstown’s stock had climbed to nearly $31 a share earlier this year, but fell to about $7 in May, after Mr. Burns acknowledged that the thousands of “pre-orders” the company had been touting were not binding orders. Some large orders the company had announced had also come from “influencers” who did not plan to buy the trucks themselves, the company said on Monday.

Mr. Schmidt, who joined Lordstown in 2019 after a stint at Tesla, said on Tuesday that the company had “binding” orders for all the trucks the company is likely to make in 2021 and 2022. But he declined to disclose the total number, name specific customers or say whether they had paid deposits to secure their orders.

“Those are firm orders,” Mr. Schmidt said. “They have been reconfirmed last week.”

Lordstown shares jumped more than 10 percent on Tuesday.

He said production would start in September even though the company’s Endurance truck has not passed all the required crash and engineering tests needed to be cleared for sale in the United States. Trucks that roll off its assembly line would be held until the testing is complete and then modified, if necessary, before being shipped to customers, a highly unusual practice in the auto industry.

Mr. Schmidt offered little detail on what prompted Mr. Burns’s departure. About a dozen other senior executives were also let go on Monday.

Lordstown gained attention in 2019 when it agreed to buy a plant that General Motors was closing. The shutdown drew scorn from President Donald J. Trump, and G.M. sold the plant to Lordstown for just $20 million. Mr. Trump later hosted Mr. Burns at the White House.

Lordstown plans to make a rugged, electric pickup truck for commercial customers like mining and construction businesses. Mr. Burns had hoped the company would become the Tesla of the pickup market. But investors grew concerned about Lordstown’s prospects after a small investment firm, Hindenburg Research, published a report in March that raised questions about interest in the company’s trucks.