[Guest]

Gentlemen,

I'm looking

Gentlemen,

I'm looking for a switch to disable my vacuum advance module when the car is at idle. Any recommendations?

I fitted a vacuum advance module to provide input to my Electromotive HPV-1 crank triggered ignition system. In general, I pleased with this modification. Cruising at highway speeds is performed at very small throttle openings which translates to improved gas milage. The problem is that the idle when hot wants to remain at 1400 rpm and the carbs cannot be closed further. What I would like to do is interrupt the vacuum signal when my foot is off the accelerator. My first thought was to utilize a stock microswitch to interrupt the vacuum signal sent to the HPV-1 ignition. I don't have one of these switches on my car now (it was removed by a PO) so I can't play with it. My reserch suggests that even if I had one, it would not be quit right in that it is closed when the throttles are on the stops. What I need is a switch that is normally closed, but open when the throttle is off the stops. I would like to mount this switch in the location normally occupied by the microswitch where it can be acutuated by the existing tab on the throttle linkage. The necessary characteristics are:

1. Normally closed
2. Open when pressed by the existing tap on the 1-2 cylinder carb linkage tab.
3. Resistant to heat and vibration
4. Mountable with a custom, rigid bracket

Any recommendations?

 

[Guest]

Hi Boll,

for something like

Hi Boll,

for something like what you describe an 80's Rolls Royce window staop micro-switch might work well and they're not very expensive considering the RR label. Or you might try going to Radio Shack or an Electronics Wharehouse as they should have micro-switches in a number of configs that should suit your purpose.

Regards, JRV

 

[Guest]

JRV,

Good thoughts. Don&#39

JRV,

Good thoughts. Don't 70's-80's domestic cars have some switches on the throttle linkages? I wounder what these might control?

 

[Guest]

Bill,

By chance, are any of

Bill,

By chance, are any of the micro-swtches on the pop-up headlights suitable...? I'm not sure if the 308s use them, but my BBs uses four of them.

Regards,
David

 

[Guest]

>>Don't 70's-8

>>Don't 70's-80's domestic cars have some switches on the throttle linkages?<<

Bill,

I couldn't say for sure if they do, certianly possible. I mentioned the others because they mount just like the orig. Ferrari micro-switch. Of course early 928 Porsches and mid year TR's have almost identical switches also.

Best, JRV

 

[Guest]

More good leads David and JRV.

More good leads David and JRV. Thanks.

 

[Guest]

After some research I haven&#3

After some research I haven't found a suitable "Push to Break" switch, so I decided to implement a different circuit to get me where I want to go.

 

[Guest]

Bill,

Your design is solid.

Bill,

Your design is solid...Nothing like using a simple relay circuit to emulate a "N.O" switch. I'd fly with that.

Best of luck,
David