Sen. Dianne Feinstein called on Silicon Valley leaders Friday to lean on Central Valley congressional representatives to get funding for the electrification of Caltrain released.

California’s senior senator — who said she’s been pressuring Transportation Secretary Elaine Chao as well as 14 Republicans in Congress who signed a letter to Chao opposing the funding — asked 400 members of the Silicon Valley Leadership Group meeting in Sunnyvale to do the same.

Caltrain officials had spent years planning the $2 billion project and lining up funding, including a federal grant agreement for $647 million. The grant was scheduled to be awarded in February but has been on indefinite hold since Chao received the letter from the Central Valley Republicans.

On Friday, inside an oversize tent on the Juniper Networks campus, Feinstein asked Silicon Valley leaders to write to Chao and the representatives and urge them to set aside politics and release the federal funds so the Caltrain electrification project can proceed.

“Help us change their minds,” she said. “This has nothing to do with the Central Valley.”

Caltrain, which carries about 60,000 riders a day between the South Bay and San Francisco, wants to convert its trains from diesel-fueled locomotives pulling bulky railcars to sleek electric-powered trains capable of higher speeds. Modernizing the 153-year-old commuter railroad, they say, would allow them to run trains more frequently and increase the overcrowded system’s capacity

Transportation was one of the marquee issues at the luncheon event. Feinstein also voiced support for a second Transbay Tube and the extension of BART from the Berryessa neighborhood of San Jose, which it’s supposed to reach by the end of the year, to downtown San Jose and Santa Clara.

Feinstein bemoaned her 1979 decision not to support a Southern Crossing bridge across the bay and said the region shouldn’t make the same mistake with a second transbay rail tube.

“I do believe we need another crossing,” she said.

Unlike recent town hall meetings, at which frustrated constituents have protested Feinstein and accused her of not being aggressive enough in her opposition to the Trump administration, the luncheon was choreographed and polite.

No protesters gathered outside the event, and nobody shouted insults or questions from the audience. While attendees dined on salmon and chicken, Leadership Group CEO Carl Guardino and Feinstein sat in white chairs on a stage and chatted, mostly congenially.

Just one issue provoked a modicum of disagreement: H-1B visas, which allow employers to hire foreign immigrants into certain jobs for up to six years. Silicon Valley companies count on the visas to fill high-tech jobs and have been irritated with the Trump administration’s seeming desire to reduce the number of H-1Bs.

But when Guardino asked about the visas, Feinstein said she was bothered when companies fire older American workers and replace them H-1B visa holders.

“We do have a problem here,” she said. “We do need to see our people have work.”

Feinstein seemed particularly distressed over the plight of Americans older than 50.

“I’m all for the young worker from another country,” she said. “What I don’t want is an American to lose the job because they (the H-1B visa holder) take the job.”

Guardino said the group would fight “any egregious if uncommon abuses,” but stressed that Silicon Valley needs high-skilled immigrant workers.

Feinstein said she supported the H-1B program “with restraints.”

After the event, Feinstein said she was hopeful Central Valley congressional Republicans will be content with having flexed their political muscles and acknowledge that the Caltrain project is crucial to the state’s economy.

As for whether she’ll seek another six years in office, Feinstein, 83, would only say: “My future will take care of itself.”

Michael Cabanatuan is a San Francisco Chronicle staff writer. Email: mcabanatuan@sfchronicle.com Twitter: @ctuan