Don't have a schematic, but I can send you a picture of my setup at some point
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Don't have a schematic, but I can send you a picture of my setup at some point
There are different ways of doing it. my favorite is to have a two position momentary on switch, one position for the full glow solenoid and one for drop voltage one (if it has the two). there are three wires leading to the switch. one for each of the solenoids and one 12v feed from somewhere that's fused, ideally.
It's not a bad thing for there to be some negative pressure in the fuel supply. If a truck didn't come with lift pump as original equipment, the injection pump is calibrated based on the sucking of the internal vane pump alone. Where the 4d55 in the Ranger was equipped with a lift pump, calibration on the test bench would be done to match with OEM supply pump pressures. The pump's internal pressures aren't going to be drastically changed with the addition of a low-pressure lift pump, but get in the ten psi range and transfer and housing pressures in the injection pump are impacted, resulting in changes to injection timing. Still, this can drastically improve the starting and performance of a badly worn/leaking pump.Quote:
Originally Posted by gard
So what supply pressures are we shooting for on a well sealed injection pump with good internal vane? the stanadyne DB2 is calibrated at 5psi because that is what the lift pump is intended to supply. The bosch VE on a 12v cummins has a regulated supply pressure of 3-5 psi. On the smaller diesels where there is no lift pump OEM, 1.5-3 psi in-line pumps will ease the burden on the IP vane pump, help purge air, and aid in the supply of alternative fuels while not restricting the flow when it is overcome by the vane pump. I suggest opting to omit the filter provided with some cheap in-line filters.
It's wise to be monitoring supply pressure. you need a gauge that reads vacuum. A boost/vacuum gauge will work. The supply "t" will be installed between the pump and the filter if the objective is to monitor for restriction and over-supply. If for example the fuel gels, you will see the gauge bottom. If for example you've added an unregulated lift pump, you will see the pressure change according to engine demand. When burning alternative oils, the addition of a e-pump can hasten the switch from diesel fuel and be turned off when the secondary fuel is up to temperature, as indicated by the vacuum/pressure gauge.
Good quality regulated e-pumps are expensive and unnecessary in most small 4-cylinder diesels with ve-style pumps. With these older trucks, often seen fuel problems relate to supply restrictions and sucking air instead of injection pump problems, and these translate into unnecessary wear on the IP's internal vane pump. Just think that there's the pickup apparatus in the tank(s), rusty sending unit and fittings, water separator and tank selector and connections (if so equipped), fuel filter and housing, old collapsible soft-lines, fuel-heater and connections all before making it to the pump connections. If a low-pressure inline pump makes a drastic improvement in performance, it's time to do some troubleshooting. If you want to do yourself and your rig a favour, learn how to use the hand vacuum pump like the mighty vac or a cheapo unit. If you're like me, you'll be glad when you discover that big, diesel-swollen bug jammed into the one-way valve of your inline pump.