safety...in - line fuel pump

[Sketch]

> My '89 system uses the oil pump switch somehow.  The pump comes on and
> runs for two seconds when the switch is turned to the on position.  If
> your pump requires more than the relay handles, can't you get a relay
> with a larger current capacity?

Are you sure about this?  On all Fieros (84-88 2.5L4/2.8V6), the oil pump
switch can turn on the fuel pump as a backup system in case the fuel pump
relay goes out.  It cannot turn the fuel pump off.  It will turn the pump
on after the oil pressure reaches ~4 PSI (during cranking).  The ECM turns
on the fuel pump relay to pressurize the fuel system as soon as you turn
the key.  That is what is turning on your fuel pump for two seconds. 

It is possible they operate differently on your car, but there's a really
easy way to check...unplug the oil pressure sender/switch while the engine
is running.  If the car keeps running, then the two systems are in
parallel like they are on the Fiero.  If not, then it looks like you are
correct, at least in the case of your car.  :)

C'ya    |  86 Fiero SE V6 4-speed  |  Space Coast Fieros
Sketch  |  Daytona Beach, FL       |  Florida Fiero Council

Florida Fiero Council & Online Service Guide:
http://apollo.pacificweb.net/~sketch/