Hi all,
I'm trying to solve a fuel / ignition problem in my '87 5000S Quattro.
About 6 months ago I bagan having hesitation problems, hard starting, weak engine until warmed up (only the first minute or so), and a smelly exhaust. It's gotten progrssively worse, and now runs with a high idle as if the mixture is very lean.
I've replaced the oxygen sensor and fuel flter, and last year the fuel pump went so I doubt its that. I've tested the mass air flow potentiometer, and the flapper moves freely. When I bought the car seven years and 250K miles ago I replaced the fuel differential pressure regulator. Does anyone suppose that this is the problem? Or does it sound like something else?
Thanks, Jaz