spf_lexus
Active Member
I noticed today my car was running much better after swapping a walbro for my stock fuel pump, which is a 190lph, not the 255. It's small but larger than stock so I know it can flow more, and it's not 18 years old! I noticed that the car is less jumpy at low vacuum, an area it used to buck and miss. It is still doing it but is tamed down... so I'm guessing I have a fuel pressure issue? The misses come when i'm usually climbing a hill or want heavier throttle in a particular gear, where the ECU would add fuel to the opening throttle plate. I have my oem fuel reg (mounted on rail) still hooked up to a vacuum source and my Rising Rate FMU in return line, BOTH ARE OPERATING. Should I just unhook the stock one and run the FMU alone? It has base fuel setting and boost onset setting. Could the stock regular possibly be counter productive with the FMU? And could I crank up the base pressure to accommodate the low vacuum situation?