Bought an 87 with lots of upgrades. Had been sitting on blocks for 12 years, long story short finally have most issues sorted out. Had to replace fuel pump and when I pulled tank found two fuel pumps. Replaced both and after following wires to 2nd pump found them hooked to a solenoid installed in fuel line then to a switch in the vacuum line. Is this something that boost in the vacuum line kicks on under certain boost to activate the pump as it is not working and what is the purpose of the solenoid? Any one with knowledge of this as I realize it is older tech as this car was built in the 90s If it is a switch where can I get a new one? I know it is not working because when I go to full throttle fuel pressure drops considerably and motor shuts down. The person that owned this car passed and I bought it from an estate sale so no history known! When I run a hot wire to pump fuel pressure goes to 63 lbs can I just hook a switch to it and manually activate it and does it cause a problem creating that kind of pressure for any length of time I am a newbee but I have really fell for this car but it is completely different from all my other cars as I was a pretty good carb guy!