Will not run right

1999 GMC SONOMA
150,000 MILES • 4 CYL • 2WD • AUTOMATIC
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SETTERGRENH
  • MEMBER
  • 80 POSTS
When the fuel pump went out for some reason I got gas in the oil. So I changed the fuel pump and fuel relay and the oil and spark plugs. I tried to start my truck and it ran rough and got gas in the oil again. However, it does not smoke and the engine light is not on. Can you Please point me in the right direction? Thank you!
May 1, 2018 at 12:18 PM
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JACOBANDNICKOLAS
  • ✓Experienced Mechanic
  • 110,246 POSTS
It sounds like you have a sticking injector which may be dumping fuel. First, make sure the fuel pressure is within the manufacturer's specs which is 41 to 47 psi key on engine off. Here are directions for testing both the pump and the regulator:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator
May 1, 2018 at 12:29 PM
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PATENTED_REPAIR_PRO
  • ✓Experienced Mechanic
  • 1,853 POSTS
Although I can find a location, is the fuel pressure regulator the type that is on the engine and has intake manifold vacuum to it? If the diaphragm busts the intake manifold could suck gasoline into the engine and eventually end up in the oil pan.
May 2, 2018 at 12:40 AM
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