dennis@home wrote:
"Christian McArdle" wrote in message
...

It is also why, on a modern diesel, if you accidentally fill with petrol,
do ABSOLUTELY NOTHING until the fuel can be pumped out. DO NOT touch the
keys or attempt to lock or unlock the doors. Otherwise, you can find your
petrol has caused several thousand pounds worth of damage to the fuel
pump.


How does petrol damage the fuel pump?



Petrol will damage the fuel *injection* pump. The fuel injection pump
operates at very high pressures, and is built to very fine tolerances.
It relies on the fuel for lubrication; petrol doesn't fit the bill. (BSI
BS EN ISO 12156-1 describes the assessment of diesel fuel lubricity, and
I seem to remember that there is or used to be a BS specifying among
other things the minimum lubricity for diesel fuel sold as such (as
opposed to central heating oil, for example.))

The very high pressures also account for the precautions taken to remove
water from the diesel before it reaches the injection pump; water in
diesel fuel can easily become acidic, and at high pressures will rapidly
dissolve pump parts and ruin tolerances.