trr777 Posted December 31, 2007 Share Posted December 31, 2007 Hi, anybody got any ideas for the plumbing of the fuel system on my 3.9efi hybrid?, slightly confused as I'm not sure if I need a low pressure pump between the fuel tank and the swirl pot and then the high pressure pump to the injectors, thanks, Tim. Quote Link to comment Share on other sites More sharing options...
TomG Posted December 31, 2007 Share Posted December 31, 2007 It can be done that way or by using a single high pressure pump submerged in the tank, if you're doing it this way, make sure you have baffles in the tank as the engine can cut out if the HP pump sucks air (e.g. when level in tank is low and on a steep gradient) Quote Link to comment Share on other sites More sharing options...
David_LLAMA4x4 Posted December 31, 2007 Share Posted December 31, 2007 Hi, anybody got any ideas for the plumbing of the fuel system on my 3.9efi hybrid?, slightly confused as I'm not sure if I need a low pressure pump between the fuel tank and the swirl pot and then the high pressure pump to the injectors, thanks, Tim. It will be a lot quicker to explain than type so if you are still stick give me a call on 01938.850382 / 07969.458958 and I will happily talk you through it - this is a job I do quite often for circuit racing customers David Quote Link to comment Share on other sites More sharing options...
trr777 Posted December 31, 2007 Author Share Posted December 31, 2007 Hi David, thanks for your offer, will give you a ring after the new year, or maybe come and see you, I'm only down the the road from you (Machynlleth) cheers, Tim. Quote Link to comment Share on other sites More sharing options...
willfromsussex Posted January 29, 2008 Share Posted January 29, 2008 I have tried external 'swirl pots' (surge tanks) when converting vehicles to EFI and they are often a bit clumsy. For it to work without an extra pump it needs to be lower than the tank (not good on an offroader!) You can run a low pressure pump to send fuel to the pot but thats one more thing to go wrong or get broken, and also use electricity. If at all possible install a submersible EFI pump inside the tank with a cup at the bottom of the tank for it to drink from. The return from the engine should be set up to pour into this cup too, so its almost like a tank within a tank, and is never lower on fuel than the rest of the tank. I have welded the top of one fuel tank (fuel pump is suspended from the top) into another fuel tank before and it worked flawlessly. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted January 29, 2008 Share Posted January 29, 2008 I have been running a low pressure lift pump into a swirl pot into a high pressure EFI pump for years and it's worked fine. Quote Link to comment Share on other sites More sharing options...
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