I have an '84GL (190k miles) with a newly rebuilt engine. It ran beautifully
before tear-down, but leaked at the heads.

Since re-installing it, I've had loads of trouble with extremely rich
running, stumbling, poor idle, small backfires in the exhaust when shifting,
and high gas consumption. I've been through the Bentley checking things and
I've found only one problem. That was a stupid move on my part when I
replaced the O2 sensor wire connector and didn't realize it was a co-ax
wire - I just crimped on a new one. Fixing that improved things somewhat,
with good idle and better gas consumption.

I'm still seeing stumbling (the AFM capacitor fix has been done, as well as
shifting the AFM internal circuit so the wiper follows a new path on the
variable resistor) and some small backfiring during shifting. With the O2
sensor (its new) unplugged, things get even better, but are not gone
altogether. I've spent tons of time checking things on this, but I'm at a
loss as to what's causing the problems. Can anyone out there make some
suggestions as to what's causing this?

Many thanks in advance...

Cliff Ober