Idle position switch question

[198491132]

Idle position switch fails continuity test. Continuity remains from idle through full throttle. Bentley 240-20 electronic test says continuity should only be upon idle.

Would this cause break up/backfire under load?

Thanks, Dave

[198491132]

Does the throttle plate basic adjustment have any relationship to a failed idle position switch? If the idle switch fails in a closed state, replacement is due, correct?

[198491132]

911-606-013-00-m100 is three weeks ship from our host..... Help!!!!!

Seems a bit much, anyone have any other solutions?

Thanks, Dave

[86 911 Targa]

Yes, but remove the wires, and see if the symptoms are still there.

[86 911 Targa]

Originally Posted by 198491132

911-606-013-00-m100 is three weeks ship from our host..... Help!!!!!

Seems a bit much, anyone have any other solutions?

Thanks, Dave

Send member Blackbyrd a pm.

Gerry

[198491132]

My switch test shows continuity 100% of time! throttle open and closed. As the switch is normally "closed" is it possible the linkage is not touching the switch during throttle opening? Thanks for the feedback Gerry.
Can the linkage be that far off? I can not tell from looking ........

[ischmitz]

Assuming you are talking about your 3.2: With the idle switch closed you won't be able to rev the engine much over 3500 RPM - that's when the fuel signal cuts out. So yes, it will cause running issues.

There is a detailed adjustment process in the WSM, The throttle plate lever should come to rest against the adjustable stop screw. Then the micro switch gets adjusted to just engage. However, the micro switch should not act as a stop itself thereby taking a hit from the drag lever every time the throttle closes.

Ingo

[198491132]

Hi Ingo, thanks for your input. Your description is exactly what is happening to my 3.2. I have tested the idle switch and there is continuity 100% as mentioned earlier. I am going to look closer and see if the linkage is so far off, it it not engaging the switch. I doubt it, but worth a look. Sal has recommended pulling the throttle body(which I have never done) to replace the microswitch. Is there a proceedure on replacing either the microswitch or the throttle body? Or is it straight forward? Thanks to All for your help on this......

[steely]

Dave,
There is an adjustment procedure in the work shop manual (WSM) that Ingo mentioned.
If your hearing is keen, you should be able to hear the switch click when the TB lever touches the switch to open it.


good luck,

[198491132]

Thanks, yes, I am looking at the manual now. Was more asking about replacement. If I need to pull the TB...or not, which is the recommended way? Never pulled it before and nothing seems to be documented. Thanks, Dave

[198491132]

Thanks All......switch was just sticking. Gunk all over.....freed up after many pushes with my fingers. Appreciate the help.....I have a lot to learn.

Dave

[hcoles]

Something I did - replace the Phillips head screws with Metric Allen head - then at least you can replace and reinstall easier. As I remember some number of the adjustment mechanism screws are difficult to get at.

[198491132]

Good idea. I did not need adjustment ...
The switch just seemed to have attracted every bit of dirt off the linkage as possible...

[famoroso]

Originally Posted by 198491132

Good idea. I did not need adjustment ...
The switch just seemed to have attracted every bit of dirt off the linkage as possible...

The Amp electrical connector on the opposite end of the switch on mine broke, due to mine missing the connector mounting bracket (that I am still in search of). I was able to repair the electrical connector with the microswitch in situ. Anyway, I am amazed at how precisely the switch is adjusted to the TB lever. You can hear the audible click at the precise moment the TB lever moves from the resting point. Gotta love the precision.