What does the Idle Switch affect?

[Axlerod]

Hey guys,

What does the Idle Switch affect? It is part of the TPS unit, as shown from the FSM:



It's meant to read 5v when the throttle is closed, and 0V when it's open. My reads 0V all the time because the switch shows no continuity when the throttle is closed.

[float_6969]

It tells the ECU that the throttle is closed and that it needs to control the idle via the AICV. Try loosening up the two screws that attach the TPS/Idle switch and move it back and forth and see if you can get continuity. If you can't the sensor is bad and will need replaced. If you can, then set it so that as soon as you start to open the throttle the circut opens.

After this adjustment, you will want to check the sensor output from the TPS portion of the sensor and make sure it's w/in the limits set by the FSM. If it's not and the only way to adjust it so that it is with in the limits is to force the idle switch not to function again, then the sensor will need replaced.

They rarely go bad and it probabally just needs adjusted.

[datsunboy]

then adjust the TPS so that it does have continuity when closed.

As far as I know, the ECU uses it somehow with open/closed loop operation.

[float_6969]

Well there is 2 requirements he's got to meet. First is that he's got continuity on the sensor when the throttle is closed. Second is that the resistance range is aprox. 1K Ohms at that same closed position, and will raise up to aprox. 9K Ohms at full throttle.

If all of these limits aren't met, the sensor needs replaced.

[Axlerod]

Thanks guys,

Ryan, as mentioned in my other thread, I've got a TPS range of 1.3k-6.8k so maybe that means I've got enough room to play with. I was hoping to just open it up and sand the contacts in there if possible. I guess I'll find out when I crack her open tomorrow!

[Axlerod]

Just an update to close this thread, I got the TPS and idle switch working.

I couldn't adjust the position of the sensor in such a way as to get continuity on the Idle Switch at closed throttle and still have more than 1k ohms resistance on the TPS sensor.

I had to open up the TPS, and to do this all I could figure was that you have to drill out the two rivets on the bottom. The cover will still snap back in place fairly securely even after you do this.

After you drill them, you cover will pop off, and all I did then was adjust (bend very gently) the arm for the switch through trial and error to have continuity at the proper position.

I now have 1.25k ohms at closed, and 7.05 at WOT. I hope that spread is enough, despite the FSM saying at WOT you should read close to 9k ohms.