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tutorial on installing isc motor on 94 cad D 4.9L


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any help in removing the isc motor (without ruing anything) i appears there is a fuel line and about at least 2 brackets and electrical wires. anything to look out for/ Thanks!

You mean a pipe over the ISC motor? That is a tube which goes to PCV valve. Disconnect it at either end and move away for a while. The screws holding the ISC motor should be carefully unscrewed (use appropriate liquid to "soften" them up).

1. Remove ISC motor.

2. Install new ISC motor.

3. Turn ignition ON (engine is not running).

4. Lift with a finger the throttle lever and press the ISC motor plunger for a while until it retracts completely (stops moving).

5. Leve the throttle lever alone so that it rests agains so called minimum air screw on the throttle body.

6. Disconnect ISC motor at its connector.

7. Turn the ISC motor's plunger using, for example a tool shown in the attached picture (it costs $0.01 lol) so that the gap betwenn the plunger and the throttle lever is about 0.030" (0.7mm pencil lead works great to set the gap) .

8. Turn ignition OFF and reconnect ISC motor and the PCV tube.

9. Done.


The saddest thing in life is wasted talent

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by the disconnect isc motor at the connector do you mean the electric connector that is held in with the clasp?

The screw on the new motor is much longer than on the installed one.

Yes, if you follow ISC motor electrical cable you will see a connector.

The length of the plungers may vary for some reason. I even had to cut one off. In ten years I have replaced three ISC motors.

Try to adjust the plunger following the instructions above. If it is too long, you can either use the plunger from the old motor or cut the new one off (make sure you have to cut off before actually doing so!).

The saddest thing in life is wasted talent

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OK I,ll give it a go to-morrow. its getting dark here thanks!

Okay, let us know if something goes wrong (should not).

Wow! a little tight spot to get the plug unplugged but perserverence paid off. I had to use the old screw as the new one was too long. It now idles at about 600 to 625 rpm and runs great. Thanks to all who pitched in .

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  • 9 months later...

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