88 80Q, Runs rough upon starting//still problems/long

[Eric Huppert]

On hot start after sitting 10 minutes or so starts, runs briefly, than
starts dropping RPM's, stumbling, etc. Car doesn't respond to throttle
unless throttle is completely opened. After several minutes of nursing it
the car will finally idle. Doesn't do this when cold...

So, per the advice of several gurus I've done the below (and way more.)

New Cap, rotor (some crud inside)
New Temp switch (top of neck)
Different ox sensor

Been working on the car for two full days now, a third of that is Bentley
"time"

Output checks (also ran codes) as listed with findings....

Diff pressure reg check (also replaced with a borrowed one): I get apx 6MA's
with car running. CO adjustment doesn't change reading. WOT switch has no
effect (should go to 100MA when switch closed) Checked supply voltage and
wiring to Ign and Fuel control units, both good

Idle and full throttle switches, wiring and voltage okay

Carb can solenoid: tested okay

Idle stabilizer checks okay, was replaced a while ago. Pulled all hoses,
checked for leaks

Cold start check valve tests okay

Altitude sensor power okay (Had blown the code a week or two ago. Shut it
off and restarted..code never came back

Replaced MFTS connector, spliced wiring as wires had broken off (I know,
doesn't do anything as far as fuel etc)

Ox sensor: Not getting the .2-.9 fluctuation at idle or higher. Did replace
it with another sensor also. Heater portion ohms out correctly...My digital
meter is a MAC Alltest, 3510 that is probably 20 yrs. old. Wondering if it's
the meter??? Picking up a new ox sensor in the morning, will see how that
acts.

Pulled fuel dis boot, checked for cracks,  cleaned air plate, ensure it
moved smoothly, etc

Per SJ I "fogged" the motor with propane... Can't find any vac leaks, nor
does enriching with propane mixture have any affect on Ox sensor voltage.

Don't believe injectors are leaking down, pulled plugs, dry... Plus this
problem just started, usually leaky injectors get worse over time! Propane
around injector seals as best I could (NG engine, manifold in way!)

I've checked wiring, vac lines, done every check that Bentley had...

Will put new ox sensor in tomorrow and try my meter on it. If meter still
doesn't work I'll probably buy another meter. Works for normal voltage, ohms
etc, thinking it possibly won't read rapid changes?

Stumped and frustrated! Not sure if I'm missing something?

Car is sold, pending I get it fixed! Don't like replacing parts it doesn't
need, but have to get it fixed right!!!!

Thoughts??????????

Eric