Two or three times a month my brothers 2005 Malibu starts and runs
rough for perhaps 5 seconds and then smooths out. He describes the
action as a "bounce" whatever that might mean. The dealer told him to
use only Shell gasoline but that didn't change anything.

Since he is not computer savvy I thought I would post this on Usenet
to see if anybody had an idea or experienced what he is reporting.