I'm working on a 2010 Camaro project and we have a Fore Innovations twin pump setup with return and vacuum/boost referenced regulator. I know alot will say just delete the FPCM and do it old school but I find this challenging to make this system work with the factory controller so that I can retain fuel pressure feedback.
With that said I am currently powering one of the two pumps from the factory FPCM since these pumps are PWM compatible I figured we could give it a try and see what happens. Thus far with only a few hours of run time on the dyno everything seems to be happy and commanded fuel pressure is achieved and held throughout various loads. I have the second pump hooked to Fores FC3 controller and is activated with a 5psi hobbs switch. I also have the regulator cranked up so that the FPCM can modulate the pump to control pressure.
I have found we don't have access to raw FPCM data stream to log so I pulled out my snap on scanner to watch raw duty cycle of the pump and found out that there are short term and long term PWM trims that the controller learns over time. Prior to seeing this I had set the regulator to 450kpa (50kpa above commanded) to give the FPCM control over the pump. I found that only 50kpa above commanded wasn't enough as the pump trims had long term learning up to around 18-20% + and short term was still positive and slowly transferring that to the long term. Pump duty cycle was hovering around 70-80% as well. So I used a little logic and thought well maybe the regulator is bleeding too much so I cranked it on down some more to reduce the free flow of the return line. This worked because pump duty cycle immediately lowered to 45-50% and the trims started lowering as well. To speed things up luckily the snap on scan tool allowed me to reset the FPCM PWM trims so I did so and to my surprise after running for 10-15 minutes the trims were +/-2%.
As of now it is looking up for the factory FPCM to control one of the F90000274 pumps. I'm just hoping that the FPCM is up to the task of the extra amperage load required of the larger Walbro. I am going to do more testing tomorrow to see how it reacts to harsher loads and monitor FPCM voltage to see if I need to supply a larger gauge wire to the FPCM to help supply the amperage draw from the larger pump. Regardless I don't think the primary pump will ever see harsh demands since the secondary pump is on a hobbs switch and when it engages is on 100% meaning duty cycle for the primary pump is going to plummet since it'll be trying to maintain 400kpa pressure while the secondary pump being on 100% will undoubtedly push it up to around where the regulator under the hood is preset to.
I wanted to post this since I've not found any "Good" information on how the system works and what people have tried doing with it. With that said has anyone else tried running a Walbro F9000267 or F90000274 pump off the factory FPCM???