Really informative article on Fuel Injection Systems - just spent the morning studying and making notes. One minor point - is there a typo/word missing in the para starting 'The HPFP pressurizes...'? The HPFP pressurizes .... Fuel is metered at the pump but a fuel pressure regulator valve on the right end of the rail also (regulates/controls??) fuel pressure in the rail by bleeding off pressure. Thanks again for the great article.