Virgin have only got to the end of a race once this season
Virgin have run out of time ahead of this weekend's Spanish Grand Prix to build two new cars with big enough fuel tanks to finish all races.
Flight delays caused by the Icelandic volcano have delayed preparations and they will have only one modified car, which German Timo Glock will drive.
Technical director Nick Wirth said the delay was "a bitter pill to swallow".
He added that Virgin hoped to improve reliability after "an extensive investigation" into their problems.
The team's poor reliability has meant that they have rarely been affected by their error on the fuel-tank size.
But the single time a Virgin car has finished a race this season, Brazilian Lucas di Grassi had to slow down to several seconds off his ultimate pace in the closing laps to ensure he could finish.
Virgin boss explains fuel tank problem
The fuel tank problem emerged after the season-opening Bahrain Grand Prix, and the team had hoped to use the three-week break between the last race in China and the Spanish event to produce two revised cars.
But Virgin said in a statement that they had run out of time because many staff were stranded in China for up to five days because of the the international flight delays caused by the ash cloud spewing from the Eyjafjallajokull volcano in southern Iceland.
Team boss John Booth said: "What should have been a useful three-week break in the calendar, and an opportunity to ensure we are fully prepared for the European season, turned into something of a race against time thanks to the fallout from the volcano.
"It took up to five days after the Chinese Grand Prix before the entire team were back in England, so we had to rush headlong into preparations for Spain.
"The planned modifications to the chassis were always going to be our most significant development, but they were also the tip of the iceberg in terms of what we will bring to Barcelona.
"As a new team we will be using new trucks and a new motorhome for the first time and on top of that we moved into our new race preparation facility while the team were stranded in China."
As well as the larger fuel tank, Glock's car will feature an aerodynamic upgrade aimed at improving performance.
Team-mate Di Grassi will have some new parts, but not the full package.
Wirth added: "Running two fundamentally different specification cars at Barcelona will certainly challenge the team, but as the reliability fixes apply to both specifications, we'll keep our heads down and focus solely on getting both cars to the chequered flag."