1996 GMC Suburban Code PO306

1996 GMC SUBURBAN
205,000 MILES • V8 • 2WD • AUTOMATIC
Avatar
JON HALE #1
  • MEMBER
  • 1 POST
I've replaced the valve stem seals, plugs, wires, cap, rotor, CPI fuel injector unit and it still runs rough when it's cold and idling. Any ideas?

Thanks.
Mar 6, 2010 at 5:26 PM
Advertisement
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.
Avatar
RASMATAZ
  • AUTOMOTIVE REPAIR CONTRIBUTOR
  • 75,992 POSTS
Engine running rough or misfiring can be cause by the following:

1.Defective spark plug.
2.Inadequate spark/coil,defective spark plug wire.
3.Lack of compression
4.False air leakage.
5.Faulty fuel injectors.
6.Insufficient fuel pressure.
7.Contaminated fuel.
8.EGR valve that is leaking.
9.Oxygen sensors.
Mar 7, 2010 at 4:48 AM