2001 suburban 5.9, 90000 mi. When its a cold start situation(morning, afterwork) the engine runs ruff. DTC is PO300, multiple cylinder misfire. After car warms up it runs fine. Mechanic says he dealt with same car & problem last year. It was STUCK VALVES. Cost 1600.00. Unable to afford this right now. What will go wrong if I continue to warm it up and drive it? Any way to stop the unsticking if this is the problem? Could it be anything else?
Stuck valves sounds a little odd, not impossible but odd. Has the truck been tuned up? If not, do so with all factory parts, cost more I know but way better and will last longer. Also after the truck has been shut off unplug the vacuum line at the fuel pressure regulator and see if there is raw fuel, big problem with those trucks. If so go to the dealer and get another. Easy fix
February, 15, 2007 AT 3:20 PM
Just wondering did this work for you I cant see vales causing this problem my truck is a 2002 cold start it sucks,68198 miles I am going to try fuel filter,clean the blade, and have the injectors cleaned.Yet me know if the fuel presure reg. help you and were the hell is it located I cant seem to find it!!!
February, 15, 2007 AT 4:14 PM
Location depends on the engine. What size is it? Chevy doesnt have a 5.9 l. If its a 5.7, the reg is located inside the intake under the top plenum, 5.3 it is located on the fuel rail on the d/s, round with a vacuum line going to intake