Mechanics

89 2WD PICKUP

1989 Nissan Truck • 4 cylinder 2WD Automatic • 139,000 miles

HOW DO YOU CHECK FOR POWER TO THE EEC UNIT, IS THERE A FUSE OF FUSIBLE LINK?
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Cactus50
April 27, 2011.




Check pin no.9, on ECCS control unit-


Tiny
Rasmataz
Apr 27, 2011.
I checked all of the wires going into the unit and had no power. Also no voltage to the wire going to the distributor and transmission shifts hard. Timming is 10BTDC and does not move when engine is reved.


Tiny
Cactus50
Apr 27, 2011.
There are 2 fuse panels/boxes: The main fuseblock is located under the left side of the dash.
The engine control fuse block is located on the left fender apron.
The fusible link is located on the positive battery cable.
Timing should be 8-12 degrees BTDC. Trans should be in Drive with parking brake set. If timing is not being advanced under throttle, there is most likely a problem with either the computer or the distributor.


Rivermikerat
Jun 14, 2011.
EEC has power but when the switch is moved from "run" to "display" it only goes through a series of 1-5 and then repeats. At idle, it runs ok, but when accelerated it gets very rich and will foul the plugs. It has new plugs, wires, rotor & cap. Firing order checked and re-checked. Also, the single wire from a "relay" in the wiring harness has no power but there is power to the relay -relay is good.


Tiny
Cactus50
Jun 16, 2011.
Check the connector at the relay output. Remove the connector from the relay and the device it powers and check continuity. Most likely the wire is broken. Also, make sure the contact points are clean and not corroded. The relay is good, this means you can activate and deactivate it yourself?

I have included 4 images with ECU pin voltages. Check the O2 sensor voltages. An overly rich condition is usually a bad O2 sensor.
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Rivermikerat
Jun 16, 2011.

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