gas in oil on 1997 Chevrolet Venture

What would cause gas in my oil. 2 quarts over full. Pressure on fuel rail test fitting is within specs but that is witout vacuum. Regulator is vacuum actuated.Is there a test for the regulator and what pressure should it be? This is 3400 v6

Asked by for the 1997 Chevrolet Venture
The most common cause for gas in the oil would be a leaking fuel injector. Does the fuel system on your 1997 Chevrolet Venture hold pressure after the fuel pump turns off - It should, if it does not you will need to find out why. How does the engine run? If a fuel injector is leaking or stuck open the engine will run rough. Also, there should be no fuel leaking out of the fuel pressure regulator at the vacuum fitting with the engine running and the vacuum hose off of the regulator.
Ty for your advice. The engine runs good and fuel pressure remains steady with key off. I'm going to pull the vacuum line while running it and check for leakage there at the regulator.
1 more answer
check the fuel pump,sometimes the diaphram will get a crack or hole in it and this allows gas to go thru and into the oil pan.This problem just happened on my sons engine.