what is a bpt valve?

[h2da3]

I have recently purchased a Chilton book to help me replace leaking fuel injectors on my 90 240sx. I am not really any sort of a mechanic, just to broke to afford paying one. It says to relieve the fuel pressure, I understand how to do that, then it says to disconnect the negative battery cable and remove the bpt valve. Now I'm lost, please help.

[U12 2NR]

BPT is the backpressure transducer valve. Which works in conjunction with the EGR valve, when backpressure is low, it insures the egr valve doen't allow exhaust into the intake.

anyway to relief fuel pressure just start the car, pull the fuel pump fuse and let the car die, then keep trying to start it to get all the fuel out of the line.

I don't see why you would need to remove the BPT unless it's in the way of the injectors. As long as you can reach the injectors fine, don't worry about the bpt. Make sure you use new o-rings on the injectors and make sure you lubricate the o-rings with petroleum jelly or so before you reinstall them.