My 85 16v had a clogged fuel distributor, tends to happen when old fuel sits in it for a while. Found my 16v in a barn, where it had been sitting for between two and three years, so there was apparently a lot of fuel residue crud in the distributor, because it had no power. I had tried spraying carb cleaner into it, and running gas with large amounts of injector cleaner through, with no success.
As an experiment (because the alternative was to replace it), I gave the distributor two hours in an ultrasonic cleaner, using parts solvent as the liquid medium. Definitely better. Another two hours, it was back to full power. A few months later, I can feel it down on power again, so it's probably coming out this weekend for one more cleaning session - I suspect the last couple of months of driving has shaken loose more old fuel residue.
I already had a 1 quart ultrasonic cleaner, just about the right size for the distributor, but you can find 1 and 2 quart models on ebay for around $100 or so. Handy things to have, and a lot cheaper than getting the distributor rebuilt or replaced.
Not sure this will solve your problem, but it sure solved mine.