Hi All, from Australia so don't know if you can help as some vehicle differences, but worth a shot.
Problem: Main fuel tank is draining prior Auxiliary long range fuel tank, problem gets worse under load ie towing (fuel empty light is coming on prior to 1 quarter line which confirms main empty before auxiliary). The problem has been there since install, when refuelling have only got through a quarter of the aux tank before the empty light comes on. The installer wants to add an inline fuel pump between the two tanks, wired to a manual switch to activate, I don't want to go down this path I want to fix the actual problem and get it fixed working like OEM setup.
Relevant Mods:
Supercharged.
Adjustable fuel pressure regulator installed and is boost referenced.
OEM fuel pump has been replaced with higher flow 340LPH (90 gallons) fuel pump, check valve on the cradle assembly has been removed and hose is connected directly to fuel pump outlet then out cradle to engine. Check valve removal from pump to prevent damage to engine under high fuel use.
OEM 45L (12 gallon) auxiliary tank has been replaced with 180L (47 gallon) auxiliary tank, retains OEM fuel transfer being venturi jet pump connected to return fuel line, auxiliary tank is supposed to drain before main tank.
Suggested causes:
Charcoal canister on main tank has failed, strong fuel smell at exhaust and high pressure release when opening fuel cap supports this. However have driven with fuel cap loose and noticed no difference so suspecting not the problem, new charcoal canister has been ordered but not installed as of yet. (common problem for age of vehicle)
Minimal fuel return due to higher flow rate fuel pump which is affecting performance of venturi jet pump. (suggested by chatgpt)
Check valve removal causing pressure issues between main and auxiliary tank, which is affecting performance of the venturi jet pump. (suggested by grok)
Venturi jet pump blocked. (common problem)
Suggested fixes:
Fuel surge tank added to address minimal fuel return with the idea a lift pump will be used in main tank and 340LPH in the surge tank. (suggested by chatgpt)
Add inline check valve to the fuel hose going between main and auxiliary tank. (suggested by grok)
Replace OEM venturi jet pump with Radium auto venturi jet pump kit which has increased flow sizes more suited to superchargers. (suggested by grok)
Attempts to fix it:
I plan on replacing charcoal canister and adding an inline check valve to the fuel hose between both tanks shorty.
Next consideration given to upgrade the OEM venturi jet with the radium auto jet pump. Lastly adding a small fuel surge tank to add the high flow rate fuel pump with the idea the return line from the engine will flow at a steady rate suitable to activate the venturi properly and constantly.
Any thoughts on whether to just proceed with all of those possible fixes straight away or fix something then test. I want to solve this problem asap and don't particularly want the hassle of sending the car away to be worked on multiple times.
Or any other causes and fixes that would be relevant to this situation?
Problem: Main fuel tank is draining prior Auxiliary long range fuel tank, problem gets worse under load ie towing (fuel empty light is coming on prior to 1 quarter line which confirms main empty before auxiliary). The problem has been there since install, when refuelling have only got through a quarter of the aux tank before the empty light comes on. The installer wants to add an inline fuel pump between the two tanks, wired to a manual switch to activate, I don't want to go down this path I want to fix the actual problem and get it fixed working like OEM setup.
Relevant Mods:
Supercharged.
Adjustable fuel pressure regulator installed and is boost referenced.
OEM fuel pump has been replaced with higher flow 340LPH (90 gallons) fuel pump, check valve on the cradle assembly has been removed and hose is connected directly to fuel pump outlet then out cradle to engine. Check valve removal from pump to prevent damage to engine under high fuel use.
OEM 45L (12 gallon) auxiliary tank has been replaced with 180L (47 gallon) auxiliary tank, retains OEM fuel transfer being venturi jet pump connected to return fuel line, auxiliary tank is supposed to drain before main tank.
Suggested causes:
Charcoal canister on main tank has failed, strong fuel smell at exhaust and high pressure release when opening fuel cap supports this. However have driven with fuel cap loose and noticed no difference so suspecting not the problem, new charcoal canister has been ordered but not installed as of yet. (common problem for age of vehicle)
Minimal fuel return due to higher flow rate fuel pump which is affecting performance of venturi jet pump. (suggested by chatgpt)
Check valve removal causing pressure issues between main and auxiliary tank, which is affecting performance of the venturi jet pump. (suggested by grok)
Venturi jet pump blocked. (common problem)
Suggested fixes:
Fuel surge tank added to address minimal fuel return with the idea a lift pump will be used in main tank and 340LPH in the surge tank. (suggested by chatgpt)
Add inline check valve to the fuel hose going between main and auxiliary tank. (suggested by grok)
Replace OEM venturi jet pump with Radium auto venturi jet pump kit which has increased flow sizes more suited to superchargers. (suggested by grok)
Attempts to fix it:
I plan on replacing charcoal canister and adding an inline check valve to the fuel hose between both tanks shorty.
Next consideration given to upgrade the OEM venturi jet with the radium auto jet pump. Lastly adding a small fuel surge tank to add the high flow rate fuel pump with the idea the return line from the engine will flow at a steady rate suitable to activate the venturi properly and constantly.
Any thoughts on whether to just proceed with all of those possible fixes straight away or fix something then test. I want to solve this problem asap and don't particularly want the hassle of sending the car away to be worked on multiple times.
Or any other causes and fixes that would be relevant to this situation?