Modified
09-08-2003, 20:17
With the bazillion post about post OEM fuel filters with a gas problem, maybe these thoughts have already been discussed, and verified true or false. I lost track, so I'll throw out a few of my thoughts.
Could some of the following issues be the cause of the gas buildup?
1). Routing of the fuel hoses. Some suggest routing the outlet fuel line from the OEM filter, under the Fuel Injection Control Module, to the inlet of the secondary filter, for that neat, out of the way look. Could this be adding extra heat to the fuel, which is promoting offgassing? Wouldn't we be better off routing hose further away from the hot engine, to reduce heat rise?
2). The ideal mounting locations would be the fuel tank lowest, then the OEM filter higher, then the secondary filter higher, and last the fuel injector pump at the highest point. If all hoses had a constant slow up, any gases would constantly travel with the fuel, and not accumulate at a unvented high point in the system. If we install the secondary filter under the air box, this filter is lower than the OEM filter AND the injector pump, and may trap accumulating gas.
3). Some mentioned starting problems, maybe due to truck being parked uphill. If this is true, maybe accumulated gas migrates with truck parked uphill, with no fuel flow, to a point where the injector pump looses suction.
4). Some people have little of no problems, like Dmaxallitech with his 30K miles. What does he know, or how did he install the system, that may be preventing problems?
I installed my Post OEM Mega filter under the air box this weekend, and here's how I routed my hose. Hopefully this can eliminate gas collection. If not, back to the drawing board.
My outlet tubing from the OEM filter is tipped up slightly. I connected hose to this OEM outlet, routed hose up 180 degrees, along the Turbocharger Air Duct, with a high point vent tee with needle valve, toward the Auxiliary battery. The tee is hose clamped to the Turbo Air Duct. This hose then continues down to the secondary filter inlet.
The outlet hose of the secondary filter is routed back toward the Auxillary battery, then toward engine, with a high point vent tee with needle valve, hose clamped to the A/C hose from accumulator. This fuel line then continues down to injector pump, with about six inches of line above engine, by injector pump , insulated.
Both of these fuel line, high point vent needle valves should ensure all gas is vented from lines, and even the filters, when the system is vented. Maybe gas could continue to collect at these high points when driving, but I could not see any hose line route that would ensure a constant slow upward, toward injector pump. I tried to keep the fuel lines away from the hot engine, to reduce offgassing.
I understand, by cutting each hose and installing a tee, with two barb adapters, a bushing and needle valve, it is a possibility for vacuum leaks, but hopefully with careful installation, no leaks are introduced. If problems arise, a lift pump may be the answer. Time will tell.
Constructive comments or criticisms are always welcome. Sharing my thoughts may spark more ideas, for a more reliable fuel filtration system.
And I almost forgot,
Could some of the following issues be the cause of the gas buildup?
1). Routing of the fuel hoses. Some suggest routing the outlet fuel line from the OEM filter, under the Fuel Injection Control Module, to the inlet of the secondary filter, for that neat, out of the way look. Could this be adding extra heat to the fuel, which is promoting offgassing? Wouldn't we be better off routing hose further away from the hot engine, to reduce heat rise?
2). The ideal mounting locations would be the fuel tank lowest, then the OEM filter higher, then the secondary filter higher, and last the fuel injector pump at the highest point. If all hoses had a constant slow up, any gases would constantly travel with the fuel, and not accumulate at a unvented high point in the system. If we install the secondary filter under the air box, this filter is lower than the OEM filter AND the injector pump, and may trap accumulating gas.
3). Some mentioned starting problems, maybe due to truck being parked uphill. If this is true, maybe accumulated gas migrates with truck parked uphill, with no fuel flow, to a point where the injector pump looses suction.
4). Some people have little of no problems, like Dmaxallitech with his 30K miles. What does he know, or how did he install the system, that may be preventing problems?
I installed my Post OEM Mega filter under the air box this weekend, and here's how I routed my hose. Hopefully this can eliminate gas collection. If not, back to the drawing board.
My outlet tubing from the OEM filter is tipped up slightly. I connected hose to this OEM outlet, routed hose up 180 degrees, along the Turbocharger Air Duct, with a high point vent tee with needle valve, toward the Auxiliary battery. The tee is hose clamped to the Turbo Air Duct. This hose then continues down to the secondary filter inlet.
The outlet hose of the secondary filter is routed back toward the Auxillary battery, then toward engine, with a high point vent tee with needle valve, hose clamped to the A/C hose from accumulator. This fuel line then continues down to injector pump, with about six inches of line above engine, by injector pump , insulated.
Both of these fuel line, high point vent needle valves should ensure all gas is vented from lines, and even the filters, when the system is vented. Maybe gas could continue to collect at these high points when driving, but I could not see any hose line route that would ensure a constant slow upward, toward injector pump. I tried to keep the fuel lines away from the hot engine, to reduce offgassing.
I understand, by cutting each hose and installing a tee, with two barb adapters, a bushing and needle valve, it is a possibility for vacuum leaks, but hopefully with careful installation, no leaks are introduced. If problems arise, a lift pump may be the answer. Time will tell.
Constructive comments or criticisms are always welcome. Sharing my thoughts may spark more ideas, for a more reliable fuel filtration system.
And I almost forgot,