Fuel pump operation

[Moneyguy1]

Now I know the philosophy re: the relay operation of the fuel pump, that in the case of an "accident" where the engine is not running, the pump automatically shuts down. But, it ocurred to me that a simpler system could be used in which a switched lead could energize a single stage relay which would close the contacts whenever the switch was in the "on" position and energize the pump (fused, of course). For safety considerations, a switch could be installed where the pump circuit could be manually turned off for those times when the key was on and the car was not running.

This would bypass that part of the computer whach on more than a few posts has failed in this respect.

I have studied the circuit and can't see a problem with this idea. Am I overlooking something?

[SoCal Driver]

There is a reason the fuel pump works the way it does. The circuit in the DME that closes the second set of contacts in the DME relay is also is part of the logic for firing the injectors. Bypassing the relay as previous posts have instructed is to show that the DME relay is not working or is to drive the fuel pump with the engine off to check the static fuel pressure.

When it's set up the way it's intended it works great.

Then it's your car if you want to monkeyfart with it.

[Moneyguy1]

SoCal

That was not the point. The point was simply to inquire rather there was an alternative that would permit the pump to work.

Sorry I even asked.

[SoCal Driver]

Yes there are many ways to work the pump besides the DME logic.

But why??? Might as well put a large illuminated button in the middle of the dash with START on it. Don't laugh it's been done.

Now you could hide a toggle that disables the fuel pump.