Mechanics

MODELS SPMTR NOT WKING, CMPTR IN LIMP MODE

1990 Nissan Other

Engine Performance problem
1990 Other Nissan Models 4 cyl Two Wheel Drive Automatic 51000 miles

Do not not drive this car a lot. Recently I noticed the speedometer working erratically. Then it would work and not work. I did not give it much attention. Until the car would not go over about 2500 rmp and gas millage became really bad. I looked into the repair manual and alldata infomation plus Atuo Zone site and determine the car is in limp mode.

I changed the speed sensor and the computer but the these did not help. I tested the battery - the result is good - 12.5V. All fuses are good.

Also, I noticed when I unplug the o2 sensor the check engine light(CEL) would not come on. The same for other sensors I unplug. The CEL would not come on.

When I remove the speed sensor I see the gear in/on the tranmission. It does not look like it is broken off. I tested both speed sensor (old & new) and they give out average.4 v. Right now the speedometer works sometimes.

Any help? Thank you.
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Aone
April 24, 2008.




Last weekend I remove the new speed sensor and put in the old one. Then I changed the speedometer. This fix the speedometer problem.

The car feel much better when driving. Feels more powerful. However, it still does not turn on the check engine light when I unplug any or several sensors.

Now I will figure out why the check engine light does not want to turn on.

Tiny
Aone
May 19, 2008.


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