[Shotimes] Smog Woes

[Alan Fanning]

Between the weather (rain), work (12 hr days), and the SHO I'm about to go
'round the bend. I figured I was a shoe-in to pass smog today with cool damp
weather and the SPOUT plug pulled. No such luck - besides running like a
pig, as you had warned, the engine wouldn't hold a steady rpm setting while
on the dyno and the test was ultimately aborted after several attempts. Last
time around (a couple weekends back) it seemed to hold rpm but wouldn't pass
on NOx.

I removed the intake last weekend to clean the EGR passages (didn't seem to
be clogged) and buggered up the gaskets in reinstalling the manifold. No
spares, so I just put it back together. No doubt this didn't help matters,
but one of the things that has puzzled me on this car from the get-go is
that, with the trans in neutral or clutch pedal in, I can't get it to hold a
constant elevated rpm below about 2000 rpm. It either scoots up or down from
the point I'm trying to hold. Seems like a connected symptom. Vac leak
maybe?  I've previously checked/replaced all the hoses and the intake
gaskets.

I've got about 5k on new plugs, plug wires, O2 sensors, IAC valve, and just
about everything else that is replaceable. I was running a 55mm MAF which I
believe to be good, and no LPM. Spec's include Stage 1 cams, SHOShop 3.2l
w/10.5:1 compression, stock manifold, new/rebuilt OEM-spec injectors. Engine
seems a little rough at idle, but I have no way of telling whether it's the
cams or something else.

Any help appreciated. I'm about to run out of time (and patience) here. It's
a pretty car but...

    Alan
    '91 SHO