Palmer did not even make the start of race two at Barcelona on Sunday, after his car broke down on the warm-up lap with a repeat of electrical gremlins which have plagued the start of his 2012 season.
iSport boss Paul Jackson revealed that the team will now switch to a new car for the next round of the series in Monaco.
"Another difficult weekend with continuing electrical problems on Jolyon's car, which have proved impossible to identify," said Jackson.
"The decision has now been taken to build a replacement car for Monaco around a different chassis and engine with all new electrical components. So the team has a busy week ahead, but will re-group in Monaco and hope to put these troubles behind us."
Jackson also praised the efforts of technical staff from GP2 and the FIA, who have helped iSport try to get to the bottom of the problems on Palmer's car.
"We have had support from the people at GP2 and some external help from the FIA technical staff, but all to no avail," he said.
"We would like to thank all who have offered help and assistance and look forward to concentrating on performance, rather than chasing a problem.
"Monaco is a special event with many good memories and results for us, so we hope to turn our fortunes around in the principality and kick start our season with some strong results."