1997 Pontiac Transport

1997 PONTIAC TRANSPORT
Avatar
KEITHS_KEITHS
  • MEMBER
  • 1 POST
Engine Performance problem
1997 Pontiac Transport 6 cyl Two Wheel Drive Automatic

when I press the brake, the engine start to idle rough, and missing badly. I was assuming that a vacum line was off. Have you every ran into this problem.
Jan 27, 2010 at 11:10 PM
Advertisement
Avatar
RASMATAZ
  • CERTIFIED EXPERT
  • 75,992 POSTS
Engine running rough or misfiring can be caused by worn or fouled spark plugs, a weak spark (weak coil, bad spark plug wire), loss of compression, vacuum leaks, anything that causes an unusually lean fuel mixture (lean misfire), an EGR valve that is stuck open, dirty fuel injectors, low fuel pressure, or even bad fuel.
Jan 28, 2010 at 3:03 AM