Contour Enthusiasts Group Archives Forums Modifications Duratec Maintenance stock 98 CSVT fuel pump flow rate

Yeah,

I dropped in a 255lph Walbro and it is a noisy, whiny bi-atch whenever the fuel drops below 1/3.
However, it has never faltered and so far run flawlessly.
At the first sign of the pump whine I checked the fuel pressure with a gauge and found it was being regulated correctly by the stock fuel pressure regulator at idle and off-idle. Therefore the whine is just the way the pump is, not because it is straining.

FYI, I used the stock pump to set down 300 wHP. I ran it at least 15 runs or more on the dyno and the Air Fuel showed that right at the top, 6000+ rpm the mixture was getting a tad leaner. It was still safe, a little over 12:1 at those high rpm. I tried to add fuel but it would not richen up, an indicator that the pump was maxed out... or injectors but they were 36# injectors and were not near max duty cycle.
With just a pump change everything richened up and I had to readjust my A/F later.

Bottom line:

If you aren't pulling close to 300 wHP, don't worry about an upgraded pump! The stock pump is more than sufficient for anything short of a "built" 2.5L turbo or a 3L turbo.