the map sensor fail means (DTC code not stated sadly)
mean the voltage is stuck at 5v or 0v.
near
the ECU never lies about this, ever.
the ECU enters FAILSAFE mode , in this case. (limphome)
and runs rich has heck , horrid rich, misfires.
RPM limited
idle controls disabled.
and retarded spark timing.
pretty much worst of the worst for EFI ops.
all you need to do is post the DTC error. and all that is what matters.
new MAP time, or fix the vacuum hose. its clogged? cracked.
make sure the vacuum leaves the intake manifold (sucks) and
makes it all the way to the MAP on the fire wall and that the
tiny filter(check valve?) inline is clogged, (blown through it)
This is a G16A ENGINE, With an ECU that does not create or control spark, (old style distributor with mech, and vac, advance)
DTC 31 or 32??????????????????????
http://www.fixkick.com/CEL/CEL.html#OBD1codes
if vacuum line is breached to map , the vacuum is not 0" HG
the MAP outputs 3.9V
the ECU trip points i do not know. but
above 3.9 or below .5v it will trip... somewhere,
here is very good map , graph
http://www.fixkick.com/sensors/my-map.html
all testing of it is here
http://www.fixkick.com/sensors/tests/MAP-testing.html
with photos and how to back probe it with an volt meter.