Fuel problem rover p6 3500 auto

[markie886]

hello

today i put the higher grade of unleaded fuel into my rover by mistake . Now the car wont idle properly and have lost a lot of power and splutters . I normally put the normal unleaded fuel in and put a lead addictive in with it.

Is it the change of fuel that has made this happen ?

thanks

mark

[JPB]

Shouldn't have thought so, as these were designed to run originally on 5 star petrol, so should be better on 99 than 95 nowadays.
You say that you've been using a lead additive, why? The V8 has no metallurgical need for that stuff so if it's an engine designed to run 5 star originally it should be fine on super unleaded and no additive.

Tesco Super (99RON) unleaded at their 24 Hour sites is now up to E7% and that's a little too much ethanol for cars with steel tanks and brass needles in the carbs, so if you've used that instead of Shell V-Power or supermarket 97, that could be the problem, but you'd be unlikely to have noticed its effects immediately unless your tank has some surface corrosion inside.

[Dave3066]

I'm with JPB on this one. I run my P6B on Shell V-Power and it runs just fine. Using a higher octane fuel should not cause the engine to cough and splutter. Possibly contaminated fuel or a problem with the carbs.

The suitability of Rover V8 heads for use without a lead replacement additive is the subject of much debate. The heads are a lightweight alloy so should have hardened valve seats fitted at manufacture. Many people, myself included, use an additive just to be on the safe side although the lead memory effect from years of 5 star usage is also reported by some as being satisfactory to allow these to run on unleaded for the rest of their useful lives.

I'm not convinced either way......

Dave