My '87 was set up with a Carter Comp. AFB plumbed to the in-tank EFI pump. The carb has an inline regulator which appears to be plumbed into a return line. The regulator spikes to 7 psi after ignition on and then jumps back to ~4 repeatedly. Q: It seems like I need to adjust the regulator down more or check the return for obstructions. Any suggestions?