I am working on a fuel system for the newer GM vehicles. It exploits the flexibility of the programming of the vehicle's ECM to control the fuel injectors based on various fuel pressures in the fuel system. I have a second pump in parallel with the original pump that activates under high load situations where more fuel is desired.
My problem now, and I half expected it, is the pressure surge when the second pump activates. Desired fuel pressure is 60psi. It jumps to around 80psi after the 2nd pump activates. When fuel demand increases enough, the pressure settles back to 60psi, but the vehicle experiences a rich spike because the ECM cannot control the fuel injectors quickly enough to compensate for the pressure surge. I tried to get a voltage reading off of the original pump so I'd know what to supply to the second pump, but I could never get a solid reading for some reason. I thought at one point I saw 8.5 volts or so. I figured I'd see what it does and cross that bridge when I got there. Well here I am!
So, what I'm thinking is put a voltage regulator in series with the supply wire to the second pump to manage the amount of voltage that the 2nd pump receives. Input voltage would be about 14V, the voltage that the vehicle's alternator supplies. Input voltage may have a +/- 1 volt swing. Max current that the pump will draw is 20A. I would like to be able to control output voltage of the regulator from 6-12V. I looked on this site and on others for a high current voltage regulator, but I couldn't find any schematics for a regulator that supplies over 1A. I was hoping someone here could make a suggestion for me? Thanks
My problem now, and I half expected it, is the pressure surge when the second pump activates. Desired fuel pressure is 60psi. It jumps to around 80psi after the 2nd pump activates. When fuel demand increases enough, the pressure settles back to 60psi, but the vehicle experiences a rich spike because the ECM cannot control the fuel injectors quickly enough to compensate for the pressure surge. I tried to get a voltage reading off of the original pump so I'd know what to supply to the second pump, but I could never get a solid reading for some reason. I thought at one point I saw 8.5 volts or so. I figured I'd see what it does and cross that bridge when I got there. Well here I am!
So, what I'm thinking is put a voltage regulator in series with the supply wire to the second pump to manage the amount of voltage that the 2nd pump receives. Input voltage would be about 14V, the voltage that the vehicle's alternator supplies. Input voltage may have a +/- 1 volt swing. Max current that the pump will draw is 20A. I would like to be able to control output voltage of the regulator from 6-12V. I looked on this site and on others for a high current voltage regulator, but I couldn't find any schematics for a regulator that supplies over 1A. I was hoping someone here could make a suggestion for me? Thanks