Hey Nissan lovers.  I just bought my second Maxima (1991, VG30E,
automatic) at a charity auction and it's had this problem ever since.
When I can get it to start, it idles very low and when I step on the
accelerator, almost nothing happens....the tach just twitches a little.
Same story when I move the throttle under the hood by hand, so its not
the cable.

I get a code 55 from the ECU diagnostics mode 3 (code 55 = normal
operation).  I've done all the ECCS sensor checks in the Haynes manual
and everything passes (though I know that doesn't mean they're really
working properly since the checks are so limited).

The distributor was worn out so I replaced it and I'm getting a good
spark.  I checked the compression - its within range and the same in
all six cylinders. The fuel pump is ok, I replaced the fuel filter,
plugs, and the throttle valve switch, but still have the same problem.

**This is interesting - changing diagnostic modes on the ECU by turning
the screw caused the idle to normalize and allowed me to rev the engine
with the accelerator for about 20 seconds.  I could only make this
happen 2 times while the engine was idling.  Similarly, I changed the
modes without the engine running (just had the key at "ON") and my
buddy said he heard the injectors click.**

So I'm guessing one of the sensors is causing the ECU to not send power
to the injectors....or the ECU is no good.  How can I find out what's
going on??  Tomorrow I'm going to check all the grounds and clean all
the connectors.  Any other ideas or guidance?  Please help.