Hi,
I have an 86 coupe, steel heads, automatic.
I've got this tapping noise coming from the engine that's loud enough to hear inside the car. At first I thought it was a lifter of something, but I took a stethscope to it and it seems like it's coming from the fuel pressure regulator. The frequency of the tapping increases with engine RPM.
I've had other cars with fuel injection, so I'm familiar with the tapping sound injectors make. This is the same, only a lot louder.
So my question: can a fuel pressure regulator make that much noise? It's an aftermarket FPR that the previous owner installed. I did check the pressure a while back and adjusted it to stock setting (I forgot offhand what the psi was). I also have a new fuel pump and fuel filter.
Thanks,
Ed

 

1st, check your vacuum source and make sure it is steady. if so, the the regulator has been known to do that.