odarp240z Posted May 5, 2012 Share Posted May 5, 2012 hello everyone, I'm thinking about swapping out my mechanical fuel pump to an electric pump but I don't really know what to do. I have a Clifford 6=8 with a 4 barrel carburetor and the set up is weird. There is two fuel line coming from the tank, one of them is a bigger size fuel line(main line) and the other is a smaller size fuel line. There are two fuel filter before and after the mechanical fuel pump. The bigger size fuel line goes to the mechanical fuel pump and the smaller size fuel line directly connects to the second fuel filter after the mechanical pump. Then connects to the carburetor. I've attached a picture to show how it looks. If I did change my set up to an electrical fuel pump, do I put a fuel pressure regulator close to where the mechanical pump was. Also, what do I with the smaller size fuel line coming from the tank. I appreciate any help I can get. Thanks everyone Quote Link to comment Share on other sites More sharing options...
beermanpete Posted May 5, 2012 Share Posted May 5, 2012 The smaller line is a fuel return to help prevent vapor lock. We mounted the pressure regulator to the fender near the original fuel filter. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted May 5, 2012 Share Posted May 5, 2012 (edited) I have some experience on this issue. I would maintain your mechanical, if it were me. Very little to gain by going electric, except additional opportunity to get stranded. I understand, though, if you have a space problem, or something like that. The electric fuel pump has to have a return line somewhere in the system to allow fuel flow to continue all the time to avoid overheating and seizing of the pump. Initially, the seizing will be reversible once the pump cools off, so just waiting for the pump to cool will get you back on the road, if only to get stranded a few miles further down the road - this can be pretty frustrating. If your fuel system is "dead-headed" (that means no return line) you will have pump overheating and reliability trouble. That doesn't happen with a mechanical pump for some reason. If you need to go electric, look for a fuel pressure regulator with a "bypass" port - I think mine was from Holley. That "bypass" port meters the amount of return that is allowed so you don't have to worry about return line diameter going back to the tank. You do hook a return line to the bypass port - I just used the stock metal return line that Datsun put in my car when they made it. That solved my electric fuel pump overheating problem. More than you asked for (and you may already know this stuff), but a few other issues I encountered along the way: Clear glass in-line filters are nice because you can see any crap in your fuel filtration, but they leak and shatter, so use them or avoid them with that knowledge. I use them if I have a dirty tank - once my tank is clean, I avoid them. Put them before the pump so they are subjected to low pressures. The cheap Mr. Gasket-style adjustable fuel pressure regulators (I think that is what the previous poster has on this inner fender) fail catastrophically and blow fuel mist everywhere when they do (I've had this happen). Ran one for years without any trouble, then all of a sudden, I had fuel EVERYWHERE-soaked entire engine compartment. I don't know how I didn't have a fire. Never thought that 3 psi could cause such a mess, but it did. My Holley bypass regulator was from Jegs or Summitt and was either $29 or $79, I can't remember - local parts house did not have one. Do yourself a favor and put a gauge on your fuel system near the carb - very helpful for trouble shooting later. Good luck. Keith I just looked at your pictures better-my previous discussion was somewhat theoretical. From your pictures you can simplify a lot. Keep your mechanical pump-you can dead-head it without a return line and it won't hurt it. You can dead-head to a 4 barrel, so you don't need a return line there either. All that return line stuff is related to the old Datsun dual carb setup that you don't have anymore. You should be able to just have the one filter before the pump. Then, run a line from your pump to your carburetor (run whatever line fits the fittings). Take the second filter off and throw it away along with the associated return line, cap the stock metal return line with a vacuum cap from the part store just to keep dirt out of it. Fire it up and look for leaks. You can do all that simplification in under an hour. If you insist on an electric pump, all that return line and regulator stuff above applies. Edited May 5, 2012 by RebekahsZ Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted May 5, 2012 Share Posted May 5, 2012 (edited) I have some experience on this issue. I would maintain your mechanical, if it were me. Very little to gain by going electric, except additional opportunity to get stranded. I understand, though, if you have a space problem, or something like that. The electric fuel pump has to have a return line somewhere in the system to allow fuel flow to continue all the time to avoid overheating and seizing of the pump. Initially, the seizing will be reversible once the pump cools off, so just waiting for the pump to cool will get you back on the road, if only to get stranded a few miles further down the road - this can be pretty frustrating. If your fuel system is "dead-headed" (that means no return line) you will have pump overheating and reliability trouble. That doesn't happen with a mechanical pump for some reason. If you need to go electric, look for a fuel pressure regulator with a "bypass" port - I think mine was from Holley. That "bypass" port meters the amount of return that is allowed so you don't have to worry about return line diameter going back to the tank. You do hook a return line to the bypass port - I just used the stock metal return line that Datsun put in my car when they made it. That solved my electric fuel pump overheating problem. More than you asked for (and you may already know this stuff), but a few other issues I encountered along the way: Clear glass in-line filters are nice because you can see any crap in your fuel filtration, but they leak and shatter, so use them or avoid them with that knowledge. I use them if I have a dirty tank - once my tank is clean, I avoid them. Put them before the pump so they are subjected to low pressures. The cheap Mr. Gasket-style adjustable fuel pressure regulators (I think that is what the previous poster has on this inner fender) fail catastrophically and blow fuel mist everywhere when they do (I've had this happen). Ran one for years without any trouble, then all of a sudden, I had fuel EVERYWHERE-soaked entire engine compartment. I don't know how I didn't have a fire. Never thought that 3 psi could cause such a mess, but it did. My Holley bypass regulator was from Jegs or Summitt and was either $29 or $79, I can't remember - local parts house did not have one. Do yourself a favor and put a gauge on your fuel system near the carb - very helpful for trouble shooting later. Good luck. Keith I just looked at your pictures better-my previous discussion was somewhat theoretical. From your pictures you can simplify a lot. Keep your mechanical pump-you can dead-head it without a return line and it won't hurt it. Remember, an electric pump does not provide any performance gain over a mechanical one - fuel pressure is fuel pressure, no matter how you get it. You can dead-head to a 4 barrel, so you don't need a return line there either. All that return line stuff is related to the old Datsun dual carb setup that you don't have anymore. You should be able to just have the one filter before the pump. Then, run a line from your pump to your carburetor (run whatever line fits the fittings). Take the second filter off and throw it away along with the associated return line, cap the stock metal return line with a vacuum cap from the part store just to keep dirt out of it. Fire it up and look for leaks. You can do all that simplification in under an hour. If you insist on an electric pump, all that return line and regulator stuff above applies. Oops - double post while trying to modify prior one. Edited May 5, 2012 by RebekahsZ Quote Link to comment Share on other sites More sharing options...
odarp240z Posted May 5, 2012 Author Share Posted May 5, 2012 I have some experience on this issue. I would maintain your mechanical, if it were me. Very little to gain by going electric, except additional opportunity to get stranded. I understand, though, if you have a space problem, or something like that. The electric fuel pump has to have a return line somewhere in the system to allow fuel flow to continue all the time to avoid overheating and seizing of the pump. Initially, the seizing will be reversible once the pump cools off, so just waiting for the pump to cool will get you back on the road, if only to get stranded a few miles further down the road - this can be pretty frustrating. If your fuel system is "dead-headed" (that means no return line) you will have pump overheating and reliability trouble. That doesn't happen with a mechanical pump for some reason. If you need to go electric, look for a fuel pressure regulator with a "bypass" port - I think mine was from Holley. That "bypass" port meters the amount of return that is allowed so you don't have to worry about return line diameter going back to the tank. You do hook a return line to the bypass port - I just used the stock metal return line that Datsun put in my car when they made it. That solved my electric fuel pump overheating problem. More than you asked for (and you may already know this stuff), but a few other issues I encountered along the way: Clear glass in-line filters are nice because you can see any crap in your fuel filtration, but they leak and shatter, so use them or avoid them with that knowledge. I use them if I have a dirty tank - once my tank is clean, I avoid them. Put them before the pump so they are subjected to low pressures. The cheap Mr. Gasket-style adjustable fuel pressure regulators (I think that is what the previous poster has on this inner fender) fail catastrophically and blow fuel mist everywhere when they do (I've had this happen). Ran one for years without any trouble, then all of a sudden, I had fuel EVERYWHERE-soaked entire engine compartment. I don't know how I didn't have a fire. Never thought that 3 psi could cause such a mess, but it did. My Holley bypass regulator was from Jegs or Summitt and was either $29 or $79, I can't remember - local parts house did not have one. Do yourself a favor and put a gauge on your fuel system near the carb - very helpful for trouble shooting later. Good luck. Keith I just looked at your pictures better-my previous discussion was somewhat theoretical. From your pictures you can simplify a lot. Keep your mechanical pump-you can dead-head it without a return line and it won't hurt it. You can dead-head to a 4 barrel, so you don't need a return line there either. All that return line stuff is related to the old Datsun dual carb setup that you don't have anymore. You should be able to just have the one filter before the pump. Then, run a line from your pump to your carburetor (run whatever line fits the fittings). Take the second filter off and throw it away along with the associated return line, cap the stock metal return line with a vacuum cap from the part store just to keep dirt out of it. Fire it up and look for leaks. You can do all that simplification in under an hour. If you insist on an electric pump, all that return line and regulator stuff above applies. Thanks for the info Keith it was very helpful. The reason I want to get rid of the mechanical pump is I live in the valley and I'm moving to Los Angeles. I'm about 2 hours away and from where I live I have to go through the mountains to get to LA. My concern about the mechanical pump is when I'm driving up the mountain the fuel cuts off leaving me stranded. I want to be able to go back and forth from time to time to visit my families. I did look for fuel pressure regulator with a bypass or return line and found a couple of them. I found some regulator with in/out inlet and bypass but has no fuel pressure mounting gauge. I found some with the same exact application and has a fuel pressure mounting gauge but has vacuum/boost port. Thought it would be easier to just buy one that has a mounting gauge so I don't have to buy the extra part for the gauge. Any recommendation to what I should use? ernie Quote Link to comment Share on other sites More sharing options...
clutchdust Posted May 6, 2012 Share Posted May 6, 2012 I respect differing opinions but I went with an electric pump too. A little hard to make out but here's a pic of my set up. Quote Link to comment Share on other sites More sharing options...
odarp240z Posted May 6, 2012 Author Share Posted May 6, 2012 I respect differing opinions but I went with an electric pump too. A little hard to make out but here's a pic of my set up. What kind of electrical fuel pump and fuel pressure regulator are you running? Quote Link to comment Share on other sites More sharing options...
clutchdust Posted May 7, 2012 Share Posted May 7, 2012 It's a Holley "red" pump and a Jegs regulator. I didn't originally plan on running the red pump, I had a Carter electric pump at first but the pump wouldn't pick up from the tank. If it was primed it would work fine, but if fuel drained out of the pump chamber for any reason, I just couldn't get it to pick the prime back up. Part of the problem is that the pump was mounted so high in the car, it likely would be fine had it been mounted farther down on the rail or something. I have not had a similar problem with the Holley pump, but it is also mounted a little lower inside the fender. As for the regulator, it was just the cheapy one that they sell but you have to be specific when you order. You have to look specifically for one with a return. I ordered what I thought was the same regulator last year for another car and it turned out not to have the return. Keep your eyes on Craigslist and I'm sure you can find a good pump. I have now bought two Holley red pumps and that Carter pump on there. I think I gave $30 for the Carter (which still works if it's mounted low enough) and $40 each on the Holley pumps. The nice thing is the Holley pumps are rebuildable. Not a big fan of Holley carbs, but I do like their pumps. Quote Link to comment Share on other sites More sharing options...
NewZed Posted May 7, 2012 Share Posted May 7, 2012 My concern about the mechanical pump is when I'm driving up the mountain the fuel cuts off leaving me stranded. Maybe I can learn something here - why would a mechanical pump stop pumping while "driving up the mountain" and why would an electric pump be different? Is the pump failing due to altitude or overheating or "vapor lock"? Just curious, what's your reasoning? Quote Link to comment Share on other sites More sharing options...
clutchdust Posted May 7, 2012 Share Posted May 7, 2012 (edited) Maybe I can learn something here - why would a mechanical pump stop pumping while "driving up the mountain" and why would an electric pump be different? Is the pump failing due to altitude or overheating or "vapor lock"? Just curious, what's your reasoning? Pretty much as you suspect, the electric pump will not be a benefit over a mechanical pump. Actually, a mechanical pump will be far better at pulling a vacuum than an electric pump. The only variable is so long as fuel still covers the pick up tube. And for that to really be a factor you need to be really low on fuel and on a really steep grade. If the OP just wants to put an electric pump on to put an electric pump on, that's a perfectly valid reason. That's basically what I was doing, just did it 'cause I wanted to. But I have no illusion I'm solving some problem that wasn't there. Oh, and for vapor lock (heat) to be a factor, the mechanical pump is relatively far away from a heat source. The engine would be having other heat issues before you would get a fuel pump related issue. Edited May 7, 2012 by clutchdust Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted May 7, 2012 Share Posted May 7, 2012 Clutchdust's setup pretty well shows all the different aspects of electric fuel pump installation and filters that I discussed. As he says too, I don't think it will solve whatever your actual problem is. If you want to spend some time describing your symptoms, most of us on the forum like a good challenge. Maybe we can help you get your car running more reliably. I mean - how steep is this hill? If your car dies on a hill, I would think about the condition of your fuel reservoirs, more specifically either your fuel tank or your carburetor float bowl. Or even a loose wire grounding out or even your battery grounding a cell out. What makes it die, then what do you do that works to get it going again? I had years of intermittent trouble with a dirty fuel tank - a lack of reliability really kills the fun. I've also had trouble with fuel mixture when changing climates, so how cold does it get when you go up the mountain? Quote Link to comment Share on other sites More sharing options...
SUNNY Z Posted May 8, 2012 Share Posted May 8, 2012 I have a pump and holley regulator I'd sell you pretty cheap. Pump is a Bosch. LMK and I can get you a picture. It was working perfectly when I upgraded for my LS1 swap. Quote Link to comment Share on other sites More sharing options...
odarp240z Posted May 9, 2012 Author Share Posted May 9, 2012 Maybe I can learn something here - why would a mechanical pump stop pumping while "driving up the mountain" and why would an electric pump be different? Is the pump failing due to altitude or overheating or "vapor lock"? Just curious, what's your reasoning? My bad on the previous post and what I was trying to say is, is there a chance that fuel wont reach the engine while going up the hill if I have a mechanical pump. Quote Link to comment Share on other sites More sharing options...
odarp240z Posted May 9, 2012 Author Share Posted May 9, 2012 Pretty much as you suspect, the electric pump will not be a benefit over a mechanical pump. Actually, a mechanical pump will be far better at pulling a vacuum than an electric pump. The only variable is so long as fuel still covers the pick up tube. And for that to really be a factor you need to be really low on fuel and on a really steep grade. If the OP just wants to put an electric pump on to put an electric pump on, that's a perfectly valid reason. That's basically what I was doing, just did it 'cause I wanted to. But I have no illusion I'm solving some problem that wasn't there. Oh, and for vapor lock (heat) to be a factor, the mechanical pump is relatively far away from a heat source. The engine would be having other heat issues before you would get a fuel pump related issue. Thanks for the explanation. Just thought that electric has an advantage over mechanical but as you mentioned it doesn't make difference. Ill keep my mechanical pump for now and maybe in the future switch to electric. Quote Link to comment Share on other sites More sharing options...
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