G-

I'm not a 1.9 expert...however, you haven't mentioned messing
with the injectors nor the idle stabilizer control unit. Either one could
cause you problems.

Try running a tank of premium(!).

Jon (The 2.1 FI Guy)

> The stumbling idle on my '84 1.9 is driving me nuts. No matter what I've
> tried, with and without the help of the goodly folks here on the list,
> nothing has helped. New O2 sensor with good ground, tested good on car.
> Compression 155-155-145-130. No oil burning, no coolant leaks, no smoke,
> plugs all textbook-beige. New dist. cap and rotor, new fuel pressure
> regulator, new fuel filter, new idle switch tested good, rebuilt AFM, AAR
> removed/cleaned/tested good in freezer and warm stove (car starts fine.) No
> vacuum leaks--vacuum tests around 13 inches, and I've pulled the vacuum
> lines time and again to check--all of them, even the ones at the AAR.
> Removed, cleaned throttle body, sealed at inlet, no light shines through
> butterfly valve. Changed oil, used Marvel Mystery in hopes that would help
> lifters if they were air locked. Used Seafoam to get carbon out of cylinder
> heads. Changed bad thermostat. Checked all grounds and built ground "web" to
> all points in engine. Checked battery voltage at startup and running (over
> 12.5). New cat, new muffler, new rear engine mounts.