auvelas Posted January 13, 2021 Share Posted January 13, 2021 Please help if possible... updating my 240z Datsun to electrical pump.. I wired everything in place utilizing existing harness from rear to the wires in front by radio.. Holley fuel regulator 1-4 psi. Im using a oil pressure switch Airtek 0S75 il to activate pump via a relay. All of which is feeding triple webers.my webers have new floats and needle and have been measured for float levels. Cars starts with no problem. I hear a constant light knocking sound of the pump being activated. My problem is my webers are flooding of fuel. I gone through everything and im at a lost. Attach is my diagram for your reference and any assistance is much appreciated. All products utilized are brand new. Could it be that I wired it incorrectly and fuel pump is power constantly. The plastic float are measured from gasket to middle. 12.5mm to the float needle. I do not have fuel return line. Im feeding carbs One after another. Also, being i see plenty of fuel i don't understand why fuel gauge never moves. Shows zero pressure. Maybe its faulty and shouldn't affect fuel flow. Help is appreciated 🙏 Quote Link to comment Share on other sites More sharing options...
NewZed Posted January 13, 2021 Share Posted January 13, 2021 (edited) 52 minutes ago, auvelas said: updating my 240z Datsun to electrical pump.. .. Holley fuel regulator 1-4 psi. my webers have new floats and needle and have been measured for float levels. My problem is my webers are flooding of fuel. Could it be that I wired it incorrectly and fuel pump is power constantly. The plastic float are measured from gasket to middle. 12.5mm to the float needle. I do not have fuel return line. So everything worked fine before with the mechanical fuel pump? Triple Webers, no return line, mechanical fuel pump, old parts in the carbs. You switched to an electric pump, and rebuilt the carbs while you were working on things? It's not going to be the wiring that is the problem. Either the pressure is too high or your new float bowl valve seats aren't sealing. Looks like you changed several things at the same time so it's hard to tell which is causing your problem. You might get a gauge and measure pressure. Don't rely on the written specifications. Also, make sure that the Holley regulator is designed to be deadheaded. It sounds like your regulator might be plumbed incorrectly. Show the plumbing diagram. Might also be that the Holley regulator spec means that it can handle 1-4 psi, not more. What pump are you using? Edited January 13, 2021 by NewZed Quote Link to comment Share on other sites More sharing options...
auvelas Posted January 13, 2021 Author Share Posted January 13, 2021 The plumbing is attached. FpR comes preset at 2.8psi and a straight forward install. Out to fuel the carbs. The other out is plugged. Fuel line in the "in" ■FPR==gauge ==DCOE==DCOE==DCOE■ The mechanical pump was non functional along with SUs needing rebuilt. I figured doing the above. Quote Link to comment Share on other sites More sharing options...
NewZed Posted January 13, 2021 Share Posted January 13, 2021 Do all of the carbs flood or just one or two? What pump? What regulator? There's a bunch of both. https://documents.holley.com/199r7914-3rev6.pdf Quote Link to comment Share on other sites More sharing options...
auvelas Posted January 14, 2021 Author Share Posted January 14, 2021 All 3 flooding. I have the part 804 fpr. Just curious. What float level do you know of for plastic float set up? Also, float needle sz200 are new and should seal shut once floats reach ball bearing. Quote Link to comment Share on other sites More sharing options...
NewZed Posted January 14, 2021 Share Posted January 14, 2021 4 hours ago, NewZed said: What pump? Quote Link to comment Share on other sites More sharing options...
auvelas Posted January 14, 2021 Author Share Posted January 14, 2021 12.426 Holley. Same flow 1.5 to 4 psi Quote Link to comment Share on other sites More sharing options...
NewZed Posted January 14, 2021 Share Posted January 14, 2021 I'm just trying to help. Sorry if I'm asking too much. Not sure what you mean by ball bearing. Almost all carb float valves are a brass needle and a rubber seat. Looks like your pump and regulator should work well together, so you probably just have to get your valve and floats working right. Good luck. https://www.holley.com/products/fuel_systems/fuel_pumps_regulators_and_filters/fuel_pumps/carbureted_fuel_pumps/carbureted_electric_fuel_pumps/parts/12-426 https://www.pegasusautoracing.com/productselection.asp?Product=1498 Quote Link to comment Share on other sites More sharing options...
tube80z Posted January 14, 2021 Share Posted January 14, 2021 16 hours ago, auvelas said: All 3 flooding. I have the part 804 fpr. Just curious. What float level do you know of for plastic float set up? Also, float needle sz200 are new and should seal shut once floats reach ball bearing. What fuel pressure you are using? Webbers generally don't need much more than 1.5 to 2 PSI. These carbs need regulators if you're system is higher than that. When I used these on my old race car I would get flooding at anything over 2 PSI of fuel pressure. Sometimes on the street 2 PSI was too much. Quote Link to comment Share on other sites More sharing options...
steve260z Posted February 1, 2021 Share Posted February 1, 2021 Get this pump. I use it https://www.racetep.com/manufacturer/carbs-and-injection/weber/electric-fuel-pumps.html Quote Link to comment Share on other sites More sharing options...
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