Question for anybody that knows: do our fuel pumps run at a constant 12 volts or does the ECM vary it based on demand? I've never had a problem with my TPI car, but i'm wondering since i'm trying to figure out fuel press problems with my son's 3000gt.....on that car the ECM cuts the voltage back to about 5 volts at idle....some times its too low.....fuel pressure is only 34 psi at idle.....i think it would run better if i wired it up to run 12 volts....but i'd like to know what our cars do first....thanks

 

3rd gens run 12 volt always - fuel pressure regulators and the return lines take care of pressure.

 

That's good to know......it's probably why when we go out to start our cars after they've heat soaked, they start and run good anyways......as i have found in helping my son with his 3000gt, those cars start terrrible when heat soaked......