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how to check idle switch?


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1990 loyale, ea82 SPFI...

 

the manual says to confirm that the idle swith is ON before adjusting timing. How do I do this? I just bought a multimeter specifically for this, but I've never used one before and I'm not sure exactly what I'm looking for here.

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idle switch is built into the throttle position sensor. threre are two connectors on it a roud one and a flat one. the flat one is the one you want. back probe both wires and if volt age is the same it should be closed. open the throttle to see the change.

 

BTW Im lazy and never seem to check that part before doing timing but if I did thats what I would do.

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back probe with both wires? :confused:

 

...please explain

 

BTW, there are 4 wires coming from the TPS (but all through the same connector)...looks like the uppermost is the one I want. Are we looking at the same thing?

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sorry my mistake what I described is on my car.:o

 

ok I looked it up for yours. its the blue with a green stripe. coming off the 4 wire connector.

 

when i say back probe I mean using a paper clip or a T pin get contact with that wire at the back side of the connector. I know its a pain but its considered shady to stab wires. there is also a way to check it at one of the diagnostic connectors(one of the big ones). the collor is the same but its hard to describe where it is without pics.

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Originally posted by rallyruss

ok I looked it up for yours. its the blue with a green stripe. coming off the 4 wire connector.

 

when i say back probe I mean using a paper clip or a T pin get contact with that wire at the back side of the connector. I know its a pain but its considered shady to stab wires. there is also a way to check it at one of the diagnostic connectors(one of the big ones). the collor is the same but its hard to describe where it is without pics.

 

You're saying there's a check connector for the idle switch specifically? I've noticed those big harnesses by the test mode connectors...I'll take a look at the diagram and see what I come up with.

 

Now once I start probing these wires, what am I looking for? Is there a certain voltage that will show on the idle switch wiring that I need to look for? Or is it something else like ohms that I'm checking? :confused: How do I know when the switch is "ON"?

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you only need to probe the one wire. If I am not mistaken you will see 5v aprx. with the switch closed

nothing (0v) with the switch open.

 

what wiring daig. are you using? you know about this right.

http://www.finleyweb.net/default.asp?id=142

 

I dont check ohms because that would only do a test of the switch itself. not a verry accurate in my opinion either.

 

cheching voltage tests the complete circit as well as the sensor.

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yeah, I've got the FSM pdf saved...I looked through it to see what voltage I'm looking for from the idle switch but I didn't find anything.

 

Anyway, I'll give it a shot this weekend and see what happens. I'm assuming if I set my multimeter to the lowest (2.5V) scale, the "ON" voltage should be enough to max it out.

 

Thanks for the replies russ ;)

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