For the past year or so, I've written a few times to get help with an
erratic idle problem. The car might stick around 900 RPM or it might
range up to 1500 or 1700, sometimes higher. Kicking the throttle might
or might not have brought it back down.

Going over my log of all the problems with this engine, it seems that
my troubles started a year ago when all the belts came off in a mess
while my wife was driving. This probably cracked a head. The head may
have already been cracked, as the car would miss under a load at
highway speed, blow off the temp level sensor, things like that. Maybe
a total of six or eight things like that. The car was clearly trying
to tell me something!

Anyway, when I recently rebuilt the car, I laid all the FI stuff aside
and did not touch it. I bolted it back on, expecting to have to deal
with the idle problem once the car was running. That has not been the
case, it idles like it did when new.

If you have a ranging idle problem, my advice is save up for new
heads. The bad mix resulting from the presence of water apparently
fools the system into some bad habits.

Jim