So. After I wrote the post above following fitting the new (Amazon) coil and an idle / fast idle test, price (!) came before a fall. Next time I went to start up it was back on 3 again - but it was a new error I've never seen before. Ignition for cylinder 1, open to earth. Reset, switched off and on again, cleared faults, no change. The new cheap coil had failed on one output even though the other cylinders that had previously been problematic were now running smoothly. Luckily Amazon took it back in 24 hours with a Royal Mail special delivery print-out label and refunded a couple of days ago, and I ordered a Bosch one (more expensive but worth it), arrived yesterday and went on at tea-time today along with the new oil cap.
This time not only did the car start and idle - smoothly and on all 4 - but then I was able to do the entire rev range without missing a beat, then drove it round the block without issue, then took it for a run up the country roads to the castle and back.
Never felt an AUA pulling like that before beyond 3000rpm - it felt more like the take-off of a Tdi hitting the torque curve than the usually rather sedate acceleration of the AUA previously. Obviously a combination of the new injectors and a properly-working coil, but really very impressed. Going to fill up tomorrow and then see how the fuel-economy goes under normal use over the next few weeks.
As a final aside - the reason for buying the cheap coil late on the Saturday afternoon was that Amazon could get it to me on Sunday. I've had adequate experiences with cheap parts before (obviously lucky) and the main thing that it proved was even though the cylinder 1 output failed near-immediately, the rest of the unit was working so much better than the knackered OEM original at 17 years old that the engine was running better than it had done probably for years. Proof enough to warrant buying the Bosch given the improved running today.
This time not only did the car start and idle - smoothly and on all 4 - but then I was able to do the entire rev range without missing a beat, then drove it round the block without issue, then took it for a run up the country roads to the castle and back.
Never felt an AUA pulling like that before beyond 3000rpm - it felt more like the take-off of a Tdi hitting the torque curve than the usually rather sedate acceleration of the AUA previously. Obviously a combination of the new injectors and a properly-working coil, but really very impressed. Going to fill up tomorrow and then see how the fuel-economy goes under normal use over the next few weeks.
As a final aside - the reason for buying the cheap coil late on the Saturday afternoon was that Amazon could get it to me on Sunday. I've had adequate experiences with cheap parts before (obviously lucky) and the main thing that it proved was even though the cylinder 1 output failed near-immediately, the rest of the unit was working so much better than the knackered OEM original at 17 years old that the engine was running better than it had done probably for years. Proof enough to warrant buying the Bosch given the improved running today.
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