930 engine swap - fuel pump wiring advice please!

cowtown · 07-18-2003, 10:33 AM

I posted this under a different topic but didn't get any replies. Can anyone with electrical experience please take a look at this circuit and tell me:

-if it will work
-if there is a better way of wiring any of it
-if I can somehow get rid of the third relay ("control relay") and still make the air plate switch work?

I've done some IC type stuf but I'm not very experienced with auto wiring.
Thanks!

dean · 07-18-2003, 02:03 PM

Colin,

It looks like it would work. I am no EE or even close. Great, now my brain hurts

Good luck

cowtown · 07-18-2003, 05:51 PM

LOL Dean, give me your address and I'll mail you some aspirin

1bar · 07-18-2003, 08:30 PM

Hey, Colin

If 87a is connected to 30 when the coil is not energized (my recollection is that 87 is normally open and 87a normally closed), then this will work. That assumes that the fuel meter plate switch closes when the car stalls - so 30 should get disconnected from 87a and the fuel pumps will shut off.

Test it before you try firing anything up. Take the relay on the bench and make sure switches the way you expect.

Wish I was still travelling to Davis every other week - I'd love to stop by and see how your project is going.

Larry

dean · 07-19-2003, 08:28 AM

Hey Colin,

One thing you have to provide is power to the fuel pumps while cranking. I don't think your diagram does that.

cowtown · 07-19-2003, 11:06 AM

Thanks guys,
Larry, there's a connection between 30 and 87a when there is no power to the relay coil, so I'm using that relay to "invert" the air meter switch's signal - that's one of the things I'm a bit iffy on. It seems to me there must be a way to hook up that air plate switch without having to have a whole separate relay for it. But I can't figure out how.

Dean, I was hoping the starter key switch connection would provide power to the relay coils in the "start" as well as "run" position, but I will have to check it with my meter I guess. Thanks for the tip!