Need a new Fuel Pump

[rv510]

My 510 seems to run out of gas every time I punch it on the freeway. I've changed the fuel filters but still the same thing. Now I'm thinking that the electric fuel pump simply can't keep up and the float bowl cant stay full. Dose anyone have any idea as to what kind of high pressure fuel pump I can get?

[nis720]

What kind of motor?

 

I have the stock 720 fuel pump for sale.

[banzai510(hainz)]

RV510

carbs want low pressure pumps.

you want 3 pounds.

Now if you have a electric pump make sure you have a regulator on there set to 3- 3.5 pounds.

 

a stock pump soould be fine also. if you still have the spacer that goes between head and fule pump otherwise the arm will bend(if you still have the offset eccentrick washer that goes on the cam bolt.

 

 

I think its more a float/needle valve in the carb issue.

make sure motor is timmed also

[datsunaholic]

Where's the pump? Electric pumps don't like to be far from the fuel source (they push rather than pull). Most CAN pull, espeically from a "high tank" like the 510 sedan, but it's not optimal.

 

Also check the lines. I've had problems from rust clogging up the hard lines between the tank and the engine. Had to blow the lines out with air. This is a particularly bad problem with non-recirculating fuel systems like the 510, since all the muck sits in the lines rather than having a constant flow like later Datsuns that had fuel return systems.

[ggzilla]

Just put a stock carb on your L-engine. You'll be driving instead of fixing...

[rv510]

What kind of motor?

 

I have the stock 720 fuel pump for sale.

 

I

[banzai510(hainz)]

pull the gas line that goes to the 32/36.

now turn the key ON. If ALOT of gas shoot out that hose I thin the line is good.

But I would still try the regulator unless the carb float isnt right.

Unless you know the exact pressure of that fuel pump. Most pumps are 6pounds and up.

 

just because it was on your friends car dont mean it was set at the right pressure. maybe when the car with twin SUs was running it was lower cause Of 2 carbs(im guessing here,making this up as I go)

 

But if line is clear and squirts alot of gas these. I say line is good.

[Logical1]

I was having the same problem on l18 with an electric fuel pump, I would floor it from a stop and after hitting about 50mph my float bowls (twin Su's) would go dry and the car would sputter and act like it was running out of gas. If I let off the pedal, the pump would fill the bowls back up it would start running fine again... new fuel filter, no problems anymore. Then I added a return fuel line to re-cyc fuel but when I stomped on it same problem... So I put a pressure sensing valve in and whenever the pressure in the return line drops it closes the valve and fills the bowls... pressure goes back up, valve opens and extra fuel starts heading back to the tank. I used a budget universal fuel pump http://www.autopartswarehouse.com/details/QQNissanQQ720QQCarterQQFuel_PumpQQ19801986QQC44P60504DP.html?apwcid=P1135867996W43b3f85c7ab9e&gan=1 (not where I got mine, but the same model) I also ran 3/8 fuel line from the tank for send and 1/4 for return. And hainz is right, put a regulator on it. Not that much more $$$ and gives you nice pressure control so you not flooding your float bowls. Not sure any of this really helps but it sounds like the same problem I was having ;)

[ggzilla]

The 720 electric pumps are 7 psi. Yes, you can run them on carbs sometimes with no problems, but carbs want 3 - 3.5 psi for best performance.