Originally Posted by Luddite
Lots of possibilities....hmm...? Pinking/pinging under acceleration is usually a sign of advanced ign timing and/or low fuel quality... though you typed that you have a NEW electronic ign system.... did the fault show up after fitting the new ign system..?

Some earlier Rover Engines were high compression and designed to run on higher octane fuel than is available at the pumps today which can cause issues...

From a poor memory I think my 85 +8 is set at 6 deg BTDC with a strobe timing light, and runs with the distributor vacuum disconnected. I did have an issue with poor fuel quality bought in a back road garage in France that caused pinking under load, it cleared when I filled up at a main line fuel stop...

If you have a weak mixture, that too can cause pinking and overheating, sometimes the engine runs on a little when the ign is switched off.. When the engine is cold the choke will be making the mixture richer.

Weak mixture/not enough fuel Rich mixture/too much fuel If you look at the spark plug electrode colours that might give you a clue ...?

I am confused re your fuel pump installation.... I have limited knowledge.... the fuel pump, stops pumping when the float in the carb closes it`s fuel supply (needle) valve, the fuel pump senses the rise in pressure and shuts off.

In an EFI system there is a higher pressure fuel pump in use that uses fuel to cool its self and such systems have pressure regulators that return excess fuel back to the tank via a seperate return fuel line...Was your car originally fitted with EFI...???


Yes this was My quandary also. Almost sounds like He has an EFI pump hooked up to His SU's.

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