Business was brisk one recent night as the smell of sizzling carne asada floated from an East Los Angeles taco truck. A row of customers sat on folding chairs, tacos and quesadillas in hand.

Two blocks down Cesar Chavez Avenue, Jesus Huerta's La Tia Tamale restaurant stood empty.

"If they weren't there," Huerta said of the shiny chrome-sided Taqueria "El Pecas" truck, "I'd be selling right now."

That may change Tuesday, if Los Angeles County supervisors place new restrictions on the mobile grills that patrons praise as icons of East L.A. life but competitors disparage as a nuisance.

"I don't think any resident of East L.A. would complain about a taco truck here," said Jorge Jimenez, who grew up nearby and now drives from downtown most days to grab lunch or dinner.

"It's a convenient service to the community."

Some taco trucks park in the same place all day, despite an existing law that requires they move every 30 minutes. But because the fine is only $60, many truck owners view it as a cost of doing business.

The new restrictions, proposed by Supervisor Gloria Molina, would increase the penalty for violating the law to a misdemeanor punishable by a $1,000 fine and/or a six-month jail sentence. To soften the blow, however, she would extend the time a catering truck can be parked in one place from 30 minutes to an hour.

Restaurant owners have long complained to county officials that taco trucks have an unfair advantage: If customers don't come to them, they can drive to the customers. And because they are small and mobile, their overhead costs are comparatively low.

"I'm for people succeeding, but it's so hard for us who are established to be able to survive," said Huerta, who has been a business owner in East L.A. for nearly 25 years.

But taco vendors see it differently: They say they provide good and affordable food to communities that sometimes lack places to eat.

"It's sort of a turf war that goes on between the vendors and the merchants," said Molina, who represents East Los Angeles. "It's a tough situation for us."

One thing taco vendors and restaurant owners agree on is that the proposed county law would put the brakes on the mobile eateries.

"Our business is a huge investment for us, and this law is going to suddenly shut us down," said Martin Velasquez, who paid $30,000 for his truck seven years ago and has been parked off Whittier Boulevard nightly ever since.

Some say that newly emerging businesses in a community with more restaurants and cafes than ever are rendering mobile restaurants obsolete -- and unwanted.

"They prohibit a community from moving forward," said Ron Mukai, a longtime developer in the community. "They make it unattractive for legitimate brick-and-mortar businesses to come in. Why would a restaurant come in when there's 10 catering trucks on Olympic Boulevard? There was a time when catering trucks filled a legitimate need because there was no willing vendor in East L.A. But for the sake of bettering the community, their time has passed."

So for the last couple of years, business owners have been pressuring political leaders to pass tougher punishments on motorized restaurants.

"All the restaurants around here, we talk and we have the same problem," said Victor Sanchez, who owns Tacos Mexico, a 24-hour restaurant on Olympic Boulevard. "I'm bringing in money for the county. But a truck? One day he's there and the other day he's not."

The tug-of-war between taco trucks and restaurants is not limited to East Los Angeles. Businesses in South Los Angeles have also registered complaints with their supervisor, Yvonne B. Burke.