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G2 18V25 Driving Walbro Fuel Pump

I am admittedly an absolute neophyte here. My robotic experience is limited to the pendant side of things (manufacturing automation applications mostly).

We will endeavor to bring some DIY automation to our farming operation in the future, but for now I am immersed in armature racing… of the automotive kind. Volvo uses a 200Hz @5V PWM control signal from the engine control module, a closed loop and table lookup strategy crosses fuel pressure and engine load axis to determine duty cycle. The 200Hz control signal goes to a pump driver module which produces an appropriate duty cycle at about 24kHz which drives the fuel pump.

The OEM pump module suffers voltage sag because of the current draw of our aftermarket high flow pump. The wiring is all 16 ga, including supply side. Aftermarket solutions exist, but are priced beyond our team budget.

Given that the voltage source (battery to fuse to relay to module) is a scant 26" long, I thought that a G2 might be able to handle this load? Given a large enough heatsink, flyback diode, and motor start capacitor, will the 18v25 allow us to take the pump output of 24kHz @14VDC, regulated down to 5V , switch it from a 10ga battery link and out to our pump? A total run of 38" of 10 ga of power wire, with a ground location nearly on the actual driver gnd pin.

If this seems stupid or marginal, that’s exactly what I expect to hear.

Draw at idle seems to settle around 2.5A, and can see 15 at full throttle with enrichment. The stall is not noted on the datasheets, and I am not going to purposely test it. System voltage is 14VDC from the alternator.

Hello, padoyle.

It sounds like you are talking about using the output of your OEM pump module (that normally drives the pump directly) as an input to the G2 High-Power Motor Driver 18v25. It is generally not good practice to use the output of one motor driver as an input to another, even if you are conditioning the output voltage down to the correct logic voltage. Additionally, it sounds like you might be talking about a full-sized vehicle. Please note that we do not recommend our products be used in projects where failure could result in injury or significant property damage.

Brandon