Help on my fuel pump prob...

[73 240Z Man]

I don't know if i should replace the manual fuel pump with an electric. Plus my stock rear electric pump is not working but has power.

Here is the thread... I posted it and got no replies...

http://www.classiczcars.com/forums/showthread.php?t=37882

Help...

[Bonzi Lon]

If you have the flat top carbs I would suggest getting the electric one replaced. If running round tops, the mechanical works fine. A couple of reasons to taking the mechanical off is it smooths out the under hood look with the block off plate. Some claim added horse power but doubt very little would be gained by removal.

Flat tops were known to vapor lock so the electric pump was used to flow cooler fuel.

My 73 has evidence of an electric at one time, it now has round tops, N-36 intakes, mechanical pump and no problems.

Bonzi Lon

[73 240Z Man]

I have tripple Mikuni's...

[Walter Moore]

I have tripple Mikuni's...

An electric might help with fuel flow in that case, but if the car runs without it the choice is likely just personal preference. Is the fuel return line still in place? Without a fuel return line the electric pump probably wouldn't help with vapor lock.

[oldhemi]

The 74 260Z has the "'73 fix for vapor lock" also. The electric fuel pump does NOT run under 400 rpm - in other words by just turning the key on. It was Nissan's method of keeping the pump off in case of accident when the motor is no longer running. I dont know for sure what method was used in the '73's.

[Bonzi Lon]

I have tripple Mikuni's...

Well now, theres your problem. (sorry, had to)

oldhemi: Unsure on my 73 electric pump system, as it was all changed over in 1980 by the dealership that rebuilt the engine.

Bonzi Lon

[zKars]

I'm running my 3.1 stroker with triple 44's off of a stock mechanical pump and nothing else. I have yet to run out of fuel doing "anything".

After an entire summer of trying to get an electric pump/regulator/return system to work well (noise levels, pressure regulation due to return restriction etc) I put the mechanical on one day as a stop gap while I was dreaming of "what the hell" do I have to do to get the electric system working reliably", and never looked back. That was two years ago....

Just make sure you have a new Nissan pump (reliability more than anything) and go have fun!

Jim