Many problems can be attributed to the Rover SD1 Efi fuel supply system due to flow and pressure issues. Because of the age of these cars (many of them subject to extended periods off the road) the primary cause is liable to be fuel contamination starting with rust in the fuel tank combined with a damaged tank filter allowing crud into the fuel pump and beyond.

If fuel contamination is not a problem or has been routinely prevented or cured the fuel pump and fuel pressure regulator, being very robust items, are less likely to fail as a result. Indeed, many of them are still operating after 25 years of service for maybe 150,000 miles and even more.

Never-the-less, when they do give problems the actual cause is often elusive because either "too high" or "too low" fuel pressure will create a "rich" or "weak" mixture respectively and, with these symptoms, other components in the Efi system tend to come under suspicion first.

For example, common faults associated with the coolant temperature sensor, throttle pot, airflow meter, extra air valve, ECU, wiring and air leaks can all affect mixture control in one way or another.

Consequently the sure way to establish the fuel supply system works correctly is to perform the prescribed tests. It’s not rocket science and needs just a little time and safe operating practice.

In fact, it is a job worth doing on a routine basis even when problems are not suspected.

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