LOWE Fuel Systems pump checking info

It is very rare to find two fuel pumps that flow the same volume at the same pressure. By not flowing your fuel pump you are making assumptions that may not be true. The best reason to flow your fuel pump is to save parts carnage, get on the "tune up" quickly and win races- these are the three best reasons, though there are many more. Without flowing your fuel pump you will never know how good (or bad) your fuel pump is. You can spend years going to the race track and tinkering with your fuel system to find your tune up and then be wrong because you may maximise your particular combination only to find out that the fuel pump was weak and your combination is based on a weak fuel pump. Flowing the whole system is recommended, but at least if you have a good pump, then what ever tune up you find you can go back to it with another good pump.

Since the fuel pump is the "heart" of the fuel system it is important to know what the pump condition is in, in relation to the nozzle sizes and the main jets and other bypass jets and poppets. The only way to know exactly what your system does is to flow it on an accurate flow bench. An accurate flow bench will tell you exactly how much fuel you are giving your engine. If your car is already running in top form then you need to know what amount of fuel your engine is getting throughout the entire rpm range. If your current fuel pump fails or wears out (they do) and you have to replace it then you need to check the system to the new pump unless you want to take 4 or 5 trips to the race track to sort out a new system. How much does it cost to go to the race track 4 or 5 times compared to getting your system flowed? A common situation is that someone will start racing and have a slightly rich fuel curve because everyone should start "safe" and find their tune up. Over the period of many races they sneak up on the tune up slowly and safely and get the car running really well. What has happened is while they were sneaking up on the main jet (taking some fuel away) the pump was wearing slightly as well taking some fuel away as well. Eventually the fuel pump fails and you have to put a new one on. If you just put a new fuel pump on the engine at this stage the car would slow down because you are "rich" with your new pump when you thought you were on the "tune up". It can be difficult to find out why because you thought you were "on the tune up". Now you start chasing weak mags, loose converters and clutches in an effort to solve the performance slump. Would it be better to know exactly how much fuel you were putting in the engine at each RPM step so you could duplicate this any time that you want? If your car is not running in top form a flow bench can give you a place to start your "tune up". Either way you have solid numbers with which to make future changes or a base line to start with.

Sample pump test sheet -
LOWE Fuel System pump test sheet sample

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