I have a 1975 280Z. I have been smelling fuel in the engine oil. I pulled the spark plugs out and they all are wet and smell of fuel. I cleaned them up and plugged them back in and left them overnight. Next morning, I pulled the spark plugs again, and they were wet from fuel. I did this a couple of times without starting the engine and same results.

Here is my question.

Can injectors leak overnight with the engine off?

What part of the injector is fuel leaking from? Is it bad O-rings? Is the injector not fully closed? Can this be repaired?

Thanks.

Well, at very least, shows that your fuel system maintains its fuel pressure. More likely, your cold start valve is leaking rather than all 6 injectors. Generally when an injector leaks, it's a bad needle valve, or something clogging it, or a bad magnet coil. I have the equipment to clean them. I have taken injectors that were clogged and cleaned them to the point where they work as they should. A bad coil requires dissambly and in that case, I toss them because those parts are hard to find and it's easier to just replace the injector. But, in your case, I'd try removing the connection and fuel line from the cold start valve, plugging tihe line. Run the car to clear out the fuel and then check fhe plugs the next morning.

Thanks Stephen. I do hear the injector clicking. Does that mean that the coil is good?

With regard to the cold start valve, can I plug the line to the cold start valve, pull the spark plugs and clean them and put them back in and check the next morning?

I dont want to start the car as I might have a blown headgasket.

The coil is the electrical part. If you hear a clicking it does mean the coil is good but there still could be dirt or grit of some kind causing the needle valve to not close all the way. The problem with checking the cold start valve the way you mention is that if you pull that line from the cold start valve, you'll release the fuel pressure which is why I suggested starting it after you plug the line.

Will do.. Thank you Stephen.