Tarzan

Guys, last Sunday my 93 GXE did not start for a long enough time and I managed to sneak under the dash to the computer and I found that it was completely turned off. There were no codes flashing.
After a minute or two of fiddling with the keys (ignition on and off) the computer started and I heard normal fuel pump noise and then the computer showed 55...

I need to tell you the history of the proble I guess.
It all started about a year ago with rare stumbling when on the highway. About half a year ago she started to stall once or twice a week and the problem is same since then.
The local Nissan dealer tried to fix it by changing the O2 sensor as per some code they have found. When the car stalled again they replaced the plugs, wires, fuel filter and did a tune up. Then they tried another distributor to no avail.
After that I took her to another mechanic who found that it was stalling with no fuel coming and he replaced the fuel pump. When this did not help he tried another computer to no avail and then replaced the power transistor.
The car kept stalling and started testing the voltage all the way from the ignition switch to the fuel pump and found that the pump was powered at all times and grounding its neg pin did not prevent the engine from stalling.
Now it gave me a few minutes to look at the codes. Before Sunday the problem would clear itself before I had a chance to even move my finger. And only to find that the whole system is off...

I had another problem with the low beam on the left about year and a half ago: the left low beam started to go off from time to time and after a couple months it would not come on at all. This was fixed by replacing the relay (some call it a switch). Right now I have a similar problem with my dimmer: both lights go on and off whenever they want, sometimes twice in a second, sometimes once a day. Looks lime all the electric parts in this car quit on me and this is happening when it has less than 100K kms on it! I am so jealous: there are lots of them running with 200-300K...

Any ideas where to look for the root of the problem with the computer power are greatly appreciated.

westsider101

the problem is your Throttle Position Sensor or (TPS).

i had the same stalling issue with myn after i took my car to have the engine bay cleaned, and the car looked clean alright! but would unexpectedly start to stall and sort of wobble all the time.

after discussing with my uncle who ownes a car part company, he determined that the issue is my Throttle Position Sensor (TPS) The sensor 'tells' the computer where the gas pedal is located several
time every second. Is it all the way up, all the way down (floored) or
some place in the middle.
and when it is burned or mailfunctioning for some reason the computer simply cannot recognize the gas pedal movement and begins to wobble.

the installation is very simple.
the sensor is located on the front right side of the engine and you need to remove a screw, unplug the sensor, remove it, and put the new one instead.
that simple.
the car will respond kind of weird for few days while the computer resets the sensor automaticly, and thats it.

mechanic wanted 600$
part is about 60-80$ (i think i got myn from my uncle)
installed in less then 10 min!!!!

hope it helps.
good luck.

Tarzan

I would have agreed if I only had troubles when driving. But do you think it all applies when the car fails to start and the computer looks like it's completely off? What really scares me is that the screw is in the diagnose position and I turn on ignition and nothing happens: no flashes, no fuel pump going, no nothing.

westsider101

then no, i guess it is not related if your not touching the pedal and the issue still continues.
my problem was when i startd driving.

sorry tho.
post if you finaaly figure it out.