mazda rx-7 fuel pump

[ricksaia]

Hello everyone. I am planning to install an rx-7 electric fuel pump on my 1970 240Z. When I wire it to keyed power, that means it will be on when my car is on? Will that be all right? Also, should I mount the fuel pump as close to the tank as possible so it is pushing fuel as opposed to pulling fuel? Hopefully someone will be able to answer my query. Thank you. Rick.

[Zedrally]

Ric,

Check underneath, you may already have wires there for an electric pump.

However, unless your are running triples or some other exotic carbie system the engine driven pump is more than ample.

HIH

[ricksaia]

I am putting an 82 280zx motor in my car with the su carbs. No place for the mechanical pump.

[mdbrandy]

I don't know about the 240Z pumps, but the FI systems on the 280Z have circuits to cut off the pump when the engine isn't running, like after an accident. The cutoff is for safety. If you just wire the pump to run when the ignition is on, then it will continue to run in an accident while the ignition remains on.

Just a thought.

[Fun_in_my_z]

If it doesnt shut off then it might catch fire. That wouldnt be good.

Brings a whole new meaning to the word hot Z.:tapemouth

[ricksaia]

Should I wire it through a relay?

Rick.

[mdbrandy]

Originally posted by ricksaia

Should I wire it through a relay?

Rick.

Somehow, you need to cut power to it when the engine is not running. In the FI system, the fuel pump contacts are in the air flow meter, so if there is no air flow into the engine, the contacts open and power is cut to the pump (probably through a relay - I'm not sure). On a 240Z, you don't have the sensors available to do this, but I'd think the later 240Z's that had electric pumps would have had some way to cut off fuel - does anyone with a later 240Z with an electric pump know how this works? My 240Z does not have an electric pump, so I do not know...

[texasz]

There was a thread on this earlier this year I believe it was. Try searching the Engine forum, that may have been where this was discussed...the cut off of an electric fuel pump that is.

Went searching and here's one such thread: http://www.classiczcars.com/forums/showthread.php?s=&threadid=7603&highlight=cut+off+electric+fuel+pump

[mdbrandy]

Originally posted by texasz

There was a thread on this earlier this year I believe it was. Try searching the Engine forum, that may have been where this was discussed...the cut off of an electric fuel pump that is.

Went searching and here's one such thread: http://www.classiczcars.com/forums/showthread.php?s=&threadid=7603&highlight=cut+off+electric+fuel+pump

Yeah, I just found that one to, but it is a bit short on specifics. Apparently beandip forgot to update it, or didn't find the part numbers.

The oil pressure cutoff actually is the way that late 280Z's and 280ZX's do it instead of the air flow meter. That's why the later 280's have oil pressure sending units that have two spade terminals instead of the single bullet terminal. I wonder if a late 280 unit could be adapted to do the job?

[ChrisA]

Hey Guys, at jegs or summit I saw a Holley oil pressure switch that would cut the fuel pump circuit if the engine quit. Maybe that would work for ricksaia. I'm not sure how its plumbed so that might cause problems as I bet its not metric pipe thread like our stock sending units. My 72 with L28 is probably not real safe as the pump runs as soon as the key gets to the ACC position. Guess I'll have to look into this also.

Chris

[Bambikiller240]

Originally posted by ChrisA

Guess I'll have to look into this also.

Hey Chris:

If you get this situation resolved on your car, let us know the particulars (P/N's, etc) as I'm sure many of us would be interested in replicating this safety system. Thanks.

Carl

[ChrisA]

Will do!!

Chris