Well if only I had taken heed of the warnings some people had posted regarding ethanol in modern fuels! I had been aware of issues with the eco-friendly E10 fuel so had diligently been using Shell V-Power Unleaded (E5). However all my recent woes (with the exception of the cooling fan) were almost certainly to have been caused by winterising the car with fuel in the car. I had even mistakenly thought that completely filling the tank just before laying it up as the best thing to do.

I had sent off the broken fuel pump to Burlen Ltd to see if it could be repaired. My two diagnoses, admittedly with the ‘help’ of wretched Google AI, were either the circuit board or the inner coil winding. The latter being terminal. Well it was none of these – Burlen investigated the pump and found the values and diaphragm had all stuck So it could be repaired.

John happened to be passing Burlen Fuel so was able to pick up the repaired fuel pump which wil be handy to keep in the boot as a spare … just in case.

This was most likely caused by deterioration due to ethanol fuel sitting in the pump for a long period of time. Over time the ethanol attacks rubber seals such as the fuel pump valve seals and diaphragm, ferrous metals as it absorbs water over time and attacks metals such as aluminium, brass, copper (essentially every component in the carburettor!) and soldered joints found in the rigid sections of the fuel line and the carburettor floats. It’s nasty stuff!

The Burlen Fuels reception areas has numerous cabinets with various carburettor and fuel pumps for all manner of vehicles plus an interesting display about the Salisbury areas war efforts in building Spitfires

Note to self: must organise the promised Spitfire flight soon!

Well back to the main topic, the car had to be left at West Tuning due to issues found with one of the jets which appeared to have sunk below the carburettor ‘bridge’. Ray’s investigation found it was the jet assembly which had failed and there was a hairline crack running along its length. As it needed to be replaced the prudent approach would be to replace all three.

Each jet had hairline fractures along their lengths

The other issue he found was that the three jets were not identical with one of them having a slightly larger bore. In Ray’s view this and the hairline fractures would have been the reason why it had never been never properly tuned before! More detailed inspection showed all three jets to have hairline cracks. The jets are not parts that should ever be under any form of stress which again pointed to the ethanol fuel as the primary suspect.

The front carb’s jet was different to the other two and had a slightly larger bore so it would have been impossible to balance all three

All three carburettors had to come off the car so Ray took the opportunity to dismantle them and put the parts through the ultrasound cleaner. Therefore it was over two weeks before the car was finally ready to be returned. Ray has mentioned that although the headline output had only increased marginally the car was much more drivable with more useful power in the mid-range.

The only thing that remained before leaving West Tuning was to take the car out for a quick road test around Thruxton’s back roads. Initial impressions were very positive and these were confirmed on the drive home. The pick up all through the range is so much better. It feels like a different car to the one dropped off a few weeks before.

Since its return it has been taken out every day …. best make good use of the heatwaves while they last!