Jump to content


Help on my fuel pump prob...

73 240Z Man

Recommended Posts

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

Link to comment
Share on other sites

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.

Link to comment
Share on other sites

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.

Link to comment
Share on other sites

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!


Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Create New...

Important Information

By using this site, you agree to our Privacy Policy and Guidelines. We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.