Truck won't stay on

[guam_napz]

I have a 84 nissan truck that won't stay on at idle checked all the plugs and everything looks good. I was wondering if the choke is stuck or my computer box is shot.

[datzenmike]

The '84s came with an 'electro carb'. If yours is the latter there is an electrical plug that connects to the carb. Nissan made the wires too short and they don't flex enough and often break internally. Try wiggling the connector or check the wire continuity with a tester.

 

Photobucket is slow this AM, I'll try later to post a picture for it.

 

 

 

If the wiring opens for the air fuel solenoid, your carb will default to a rich condition. You may notice black smoke from the tail pipe, rough idle and a reduction in fuel economy.

 

If the anti-dieseling solenoid circuit is open, the solenoid will fail shut and your engine will cut out.

 

If the throttle valve switch circuit is open, the ECU will think the engine is at idle or decelerating (depending on the engine RPMs) even when you are actually cruising or accelerating. If the ECU thinks the engine is decelerating, it will turn on the anti-dieseling solenoid and shut off the fuel flow, causing the engine to cut out under load. However, when you push in the clutch, the ECU then knows that the engine is out of gear and will disengage the anti-dieseling solenoid and the engine will idle just fine.

[datzenmike]

OK here's a picture of the ECC plug.

 

http://i138.photobucket.com/albums/q251/datzenmike/Z24electriccarb.jpg[/img]"]

 

Here's a wiring diagram with color codes.

 

http://i138.photobucket.com/albums/q251/datzenmike/ECCelectrocarbZ24engine.jpg[/img]"]

 

And again, here's what happens if one (or more) wire fails.

 

If the wiring opens for the air fuel solenoid, your carb will default to a rich condition. You may notice black smoke from the tail pipe, rough idle and a reduction in fuel economy.

 

If the anti-dieseling solenoid circuit is open, the solenoid will fail shut and your engine will cut out.

 

If the throttle valve switch circuit is open, the ECU will think the engine is at idle or decelerating (depending on the engine RPMs) even when you are actually cruising or accelerating. If the ECU thinks the engine is decelerating, it will turn on the anti-dieseling solenoid and shut off the fuel flow, causing the engine to cut out under load. However, when you push in the clutch, the ECU then knows that the engine is out of gear and will disengage the anti-dieseling solenoid and the engine will idle just fine.

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