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Hello, ok, as far as i know what you usually do to check idle speed is to connect a normal Tachometer to the negative cable of the primary side of the ignition coil and the + and - of the tachometer to battery.
You should also unplug the Engine Fan connectors and clear any error codes stored in the computer if there's any.
Also check and adjust if necessary the ignition timing before doing the idle speed test.
Don't forget to re-connect the fan connectors....
 

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philippe said:
The engine dies when I hook up the tach to the wire comming out of the coil going into the distributer. I assume that it is the negitive terminal because current runs from negative to positive.
That's correct, because you're unplugging the primary supply of power to the coil, what you should do is to get to the - wire without unplugging it from the coil like with some "pass'trough" adapter (suitable tool ;) ) or being extremely careful try to insert a thin needle inside the cable or into one side of the connector so it makes contact with the wire and connect the tachometer to the needle. Make sure you have the wiring diagram for the tachometer you're using. Also check that the tach. is for four cilinder engine or has a switch to select between 4, 6 and 8...
 

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philippe said:
The engine dies when I hook up the tach to the wire comming out of the coil going into the distributer. I assume that it is the negitive terminal because current runs from negative to positive.
UUPS, kindda sleepy here.... the cable you're disconnecting is the SECONDARY side of the coil it is the big one thath goes from the coil TO the distributor and has HIGH VOLTAGE, make sure not to touch it when also being in contact with chassis ground or you will remember it for a while.... :D also don't connect the tachometer to that cable or probably it will die, you should get to the primary cables, they came from engine wiring to the coil and it's an small connector with 2 wires on it, one positive, one negative.
 
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