[TECH] Cis to CIS w/ Knock Box

[tberk@mindspring.com (T Berk)]

Dan Bubb wrote:
> 
> Yeah, the 16V has two switches. WOT switch up on top in the "normal" place
> and the idle switch underneath the primary plate.
> The knock ignition needs two switches. An idle switch and WOT switch.
> Fuel needs only the WOT switch.
> On the 16V with CIS-e they are integrated. The WOT switch provides input to
> both the fuel computer and the knock box.
> On your car with CIS you will need the idle switch and TWO WOT switches. You
> need two WOT switches because for the fuel the pin on the computer gets
> grounded when the switch is closed and for the ignition the pin on the knock
> box is supplied 12V when the switch is closed.
> So, you can do this two ways:
> 1. piggyback the two WOT switches on top of each other. This is pretty easy
> to do. The downside is the extra weight of the additional switch kept
> breaking the switch bracket! Really! I ended up welding a 3/16" bar across
> the area that kept breaking.
> 2. Wire the output of the ignition WOT switch to a relay (and also the knock
> box, of course) and have the relay ground the pin on the fuel computer.
> Little wiring work, but I bet that goddamned switch bracket won't keep
> breaking!
> 
> I know this seems like a PITA, but for the knock ignition to work correctly
> it really needs both the idle and WOT switches and, of course, we know the
> fuel computer needs it's little WOT switch or the mixture is too lean for
> max power.
> HTH
> If this still isn't clear keep asking and I'll see if I can word it
> differently to get you over the hump.
> Dan

<snip>



Dan,

My original CIS didn't come with throttle switches, it's CIS w/ O2
sensor. (1981) OTOH, The A2 GTI donor (K/S box, partial loom, A2
Throttle w/ two switches, and long block) _did_ come with the just
mentioned WOT & Idle switch. 

So, I'm confused about needing three switches.

Could you strip it down to a basic "under the following constraints,
set of conditions you need the following"... type explanation?

Partly adding to my confusion is that I'm reading into your post above
the addition of a K/S system to a 16v. Ummmm. Help.


TBerk