Quote:
Originally Posted by Joe AZ
Where do those running Airtex, or any fuel pump for that matter, pull power for the pump? Would a relay be advisable, or necessary?
Joe
|
Holley sells an oil pressure switch that you can run power thru, the idea being that if there's a leak in the line out of the pump, the engine will die and it will shut off the pump to prevent a fire. On modern cars they use the computer to detect whether ignition pulses are present or not, and EFI engines will stop almost immediately on loss of fuel pressure. On our cars, the oil pressure switch is for some kind of crash where the line gets ruptured and the driver is unable to shut off the ignition. In normal operation, by the time the carb has run out of fuel, and the engine stopped, you've pumped a lot of gas all over the place, can smell it, or see the flames.
Obviously if you use the switch, you've got to provide power to the pump until you've got oil pressure (probably before cranking to fill the carb). Older Chrysler products had a timing relay that energized the pump for 5 seconds after the ignition was energized, or when the starter was activated. That would be perfect but I can't find one.
http://www.holley.com/12-810.asp