Nissan Repair: 1987 300zx 2+2 bacfire/rough idle problem, leaky injector, pressure test

Question
I recently installed and after market fuel pump in the car and
now it has backfiring and a rough idle. I adjusted the idle
control valve to where most  of the problem is gone but is
there something else I can do in order to smooth this out?

Answer
Michael,

Look for leaky injector or two and replace them.  Do a fuel pressure test.  Turn the key off and I bet the pressure drops to zero almost instantly.  If this is the case, remove plugs and look for the ones that are wet and black and you have found your leaky injectors.  Replace the problem injectors and you should be fine.