So I bought this 89 Iroc Z28 Convertible 5.0 tpi, ran when I bought it, got it home and was looking over everything (bought it as a project car) pulled the dipstick and there's fuel mixed with the oil. Am I right in thinking a possible injector leak or maybe the fuel pressure regulator? Previous owner said they replaced the injectors and rebuilt the regulator. Thanks for any help!

 

first thing id do is check your compression and do a leakdown test to establish the health of the cylinders. drain the oil out into a clear bucket as well and let the oil and fuel seperate to judge just how much fuel is leaking into the oil. its possible that the piston rings are allowing fuel to get past them, you'd also see other signs like excessive crankcase blowby. but definitely start with the basic compression/leakdown tests and report back with your findings.

if those tests come back okay, next thing id check is for the injectors to be stuck open dumping fuel.

also are we talking about stock fuel system? fuel pump, fp voltage, injectors, line pressure etc? more information always helps