I've had quite the saga on my 2003 Chevy Blazer LS 4WD 4.3L with 159K miles and I am nearing the finish line of replacements. I found a great shop that I've been working with that has been working with me on my persistent P0300 code. We replaced the distributor and corrected a vacuum leak.

I'm still having issues.

Here are my symptoms:

• P0300 trouble code (persistent)
• P0442 trouble code (EVAP leak)
• Hard cold crank (takes 2-3 seconds to start the engine)
• Horrible gas mileage (10mpg/city)
• Erratic acceleration and RPM's all over the place (revs to 4500 to get to 2nd and 3rd gears)

I've replaced everything associated with a P0300 code, except the fuel pressure regulator.

My best-educated guess (and my mechanic alluded to this to be a problem) is that the fuel pressure regulator is the issue. I've seen some videos online, but I wanted to see if there was a good step-by-step guide to replacing this part.

 

Has anyone pulled the spark plugs out and checked their condition? Not sure I go with the fuel pressure regulator (FPR)....I am thinking the fuel injection spider is more likely, although a 2003 should have come with the improved design spider....guess they can fail as well.

Do you have fuel pressure readings? (key on, engine off).

Taking the air plenum off is not all the difficult. Once off, easy to see if FRP is leaking. Also would suggest replacing the lower intake gasket as the OEM leaks. You can find alot of steps on replacing it.

Nice looking Blazer!!