24-02-2020, 10:45 AM
Hi Mike, I don't claim to be an A7 expert [my expertise, such as it is, is with much much more modern vehicles] but I think you might be on the right track looking at the ignition side of things as the symptoms you describe also fit the parameters for an low HT secondary voltage.
The vehicle has never run right for you, so I suspect the problem is still on the car [if you know what I mean].
At the very least the carb reconditioner will have sent back a very clean carb and you have tried an independent fuel supply and a substitute carb, and checked for vacuum leaks as others have suggested to no avail.
You mention you have electronic ignition fitted?
FWIW try connecting a xenon timing light/neon timing light to the main coil to distributor lead and see what happens to the flashing rate when you try to rev up the engine, this is a rough and ready way to see whether you have a total ignition cut. Also check the HT lead integrity esp. if the are the non-metallic "carbon" ones. Might also be worthwhile temporarily connecting the appropriate coil terminal directly to the correct battery terminal to bypass all the potential voltage drops. Don't forget primary system voltage and the earth return side of the ignition system as well.
Could be an esoteric A7 issue in which case one of the real experts will have other ideas.
Good Luck, and as one of my old Service Managers used to say, if one bloke has [insert adjective] it, another bloke can fix it
AGW
The vehicle has never run right for you, so I suspect the problem is still on the car [if you know what I mean].
At the very least the carb reconditioner will have sent back a very clean carb and you have tried an independent fuel supply and a substitute carb, and checked for vacuum leaks as others have suggested to no avail.
You mention you have electronic ignition fitted?
FWIW try connecting a xenon timing light/neon timing light to the main coil to distributor lead and see what happens to the flashing rate when you try to rev up the engine, this is a rough and ready way to see whether you have a total ignition cut. Also check the HT lead integrity esp. if the are the non-metallic "carbon" ones. Might also be worthwhile temporarily connecting the appropriate coil terminal directly to the correct battery terminal to bypass all the potential voltage drops. Don't forget primary system voltage and the earth return side of the ignition system as well.
Could be an esoteric A7 issue in which case one of the real experts will have other ideas.
Good Luck, and as one of my old Service Managers used to say, if one bloke has [insert adjective] it, another bloke can fix it
AGW