4.3 vortec running rich

94 Silverado. I'm blowing blue smoke at startup and revving the engine. It's clear that it's running rich. No trouble codes and everything with parameter. Computer reset by disconnecting battery. It was much more evident after reset until the computer 'caught up'. Previous msgs. suggested the fuel pressure regulator. This was changed without effect. Any suggestions?

94 Silverado. I'm blowing blue smoke at startup and revving the engine. It's clear that it's running rich. No trouble codes and everything with parameter. Computer reset by disconnecting battery. It was much more evident after reset until the computer 'caught up'. Previous msgs. suggested the fuel pressure regulator. This was changed without effect. Any suggestions?


Blue smoke indicates that you are burning oil.
Blue smoke at start-up..I would check the valve stem seals

No, this is dark and smells of fuel. Valve seals are fine, oil is clean. most definitely burning rich. especially on the first start up of the day.

I had a 93 4.3 with the same problem, replace the injector/regulator/spider assembly.. It leaks fuel and fills up the manifold creating a very rich condition most noticeable during startup.