Originally Posted By: Number_35
Hey, who else has purchased a miracle automotive product only to find it didn't work? Here are a few that come to mind:
About two and a half years later, I purchased a Cagle fuel pressure regulator from the Minit-Tune shop where I worked as an oil change & tune-up tech. I pulled in $3.75/hr. (Classic Liberal Arts grad story.) The principle was that a mechanical fuel pump was designed to produce sufficient pressure for open throttle operation (5-7 PSI) but that at idle and cruise 1-1/2 PSI was sufficient. However, the fuel pump's unregulated pressure would overwhelm the needle & float mechanism in the carb at idle and cruise, forcing extra fuel into the float bowl.
The Cagle spliced into the fuel line before the carb, and was regulated by vacuum from the intake manifold. High vacuum = low load = low fuel pressure requirement. Low vacuum = high load = high fuel pressure requirement.
Again, underwhelming results ... no measurable change in gas mileage. That one was $92.50 plus tax. At $3.75/hr, that one ate up the better part of a week's wages...
The Cagle did indeed work, but was never intended to affect fuel economy. It only provided low fuel pressure at idle to the old Stromberg 94/07 carbs that couldn't withstand high fuel pressures...FWIW