Drove my 90 GL w/248k on the ODO(Boston Bob rebuild at130k) to work
last week with no problems.  1 hours later when I try to start it to
go home, it did start sorta, but wouldn't build up RPMs and was
running WAY rich.  Checked compression and had the following  1-165
2- 135, 3 -95, and 4- 135.  Don't think that's the major problem,
though.  Towed it home and still haven't figured out the
problem.  Since this engine has an old school Haltech engine
management system on it instead of the Digifant, many of the usual
Vanagon issues might not apply here.  I unplugged the O-2 Sensor and
there was no improvement.It acts like there's some sort of
restriction in the exhaust system, but how could it run fine, get
shut down, and then later in the day not hardly run at all?  I was
going to remove the Cat and see if it was clogged up, but thought I'd
check the other stuff first.  The Haltech System is like 10 years
old, so maybe something like the Throttle Position Sensor might be
bad??  It runs off of a 1 bar MAP sensor.  I've checked for vacuum
leaks, but something this bad you would think you'd be hearing the
hissing if a hose were off or worn through somewhere.  I should try
and start it again and see what the vacuum gauge is reading.

Could it be something as simple as the fuel pump/filter?  I pulled a
fuel line off the other night and got spritzed with the pressure from
the line, so I don't think it's a lack of fuel pressure.  The fuel
pressure gauge has been reading low for over a month now(like 15-20
PSI rather than the 29-36 range), but that hasn't stopped it from
running. normally.  FP Regulator toast???

Any suggestions would be welcome at this point!!!

TIA

DM&FS