87 rx7 t2 wont start
 

I switched my Rx7's fuel pump and the FPR back to the stock one because it had a different one
after that it no longer started
recently i checked to see how the injectors were and they work i checked the
cables off the harness to see if they were providing the proper voltage
after i put everything back to together it actually started but it wouldnt stay on
without holding the gas pedal. after it shut off it wouldnt start anymore
put more gas in the tank and now doesnt start anymore

fuel is either not gettting in the engine or could the fpr not have enough vacuum and
too much flows in the engine?
is there something i can check

are you sure your stock FPR is still good? it has a rubber diaphragm internally and they really don't like sitting on the shelf after being used for 20 years... makes things angry.

bought it and said it was good working like new
ive checked the return line and little bit of gas comes out
is there a way to check it? or it either works or doesnt?