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Knock box + ICM wiring diagram?

48K views 33 replies 12 participants last post by  VenousSAGE 
#1 ·
I decided to run a knockbox and a 7 pin icm setup with my carbs and am having trouble finding a good diagram to follow. Ive been searching for a while and cant turn up what I need. All I can find are people saying "Yeh, I run a knockbox setup"
 
#2 ·
The diagram from a Bently for any 16V with cis-E like what a 16V Scirocco runs should work. Since the spark is independent of the fuel, all it needs is power, a vacuum signal and the signal from the dizzy to work.
 
#4 · (Edited)
Do you have the Bently Manual for the car this came from? I think it should show how the pins are ordered out in the connector. Or you can look on the connector for the pin numbers. And the wire colors are on the diagram, you should be able to figure it out with those alone.
 
#6 · (Edited)
FV-QR

generally in the computing world a 15 pin connector would have this sort of standard pinout...


Note that it says male connector, that's the half with the pins sticking out if you weren't sure, a female connector has holes instead of pins ;)

NOW as far as the knock box is concerned, i really don't know for sure
 
#8 ·
this doesnt seem too complicated to me, plus the benefits of it are great compared to others. Running a knockbox is about as good as its going to get next to programmable, which will be my next step once cash allows. The knockbox has a 3d timing curve which is what im after.
 
#13 · (Edited)
If anyone could help me out with wiring it would be greatly appreciated, I only have 3 wires left that are unknown. Ive looked at 3 diagrams and cant figure it out, I know brown is ground but why two? One wire is green\yellow the other two are straight up brown

By ncbrock at 2011-12-31

Also according to all 3 I should have two brown\yellow's (which I dont) and on the 2nd diagram it says for the brown\yellow to go to the starter, and on the 3rd diagram it says for the brown\yellow to go to the fuel pump (which you cant see)


By ncbrock at 2011-12-31


By ncbrock at 2011-12-31


By ncbrock at 2011-12-27
 
#19 ·
Dunno, when we removed the harness for the knock box/spark control on the 16V Scirocco, everything was on the motor side of firewall, nothing went inside the pass compartment. Another reason to have the correct tools.
 
#22 ·
This makes no sense. The connector is what tells you which terminal. Let's try this a different way...

Does your mystery wire come form the knock box or the ICM?

With the (insert source of mystery wire here) sitting flat on the mounting surface on a table with the connector facing you start at the left pin (#1) and count to the right until you get to your mystery wire.
 
#26 ·
ive got that one and a golf\jetta one. Unless you spend a lot of time studying the current flow diagrams, they dont make a whole lot of sense. I can make out some things but id need someone that knows what they are looking at beside me to tell me 100%
 
#29 · (Edited)
WATCH OUT for the screwy wiring advice here.
"Drivers Found" is just another Vortexer who can make a mistake like anyone.

That mystery wire from the KNOCK BOX to the STARTER 50 (Solenoid 12V during cranking) ncbrock has an issue with, supposedly from T10 on the Knock Box. Obviously there is no reason at all to send 12V into T10 of the Knock Box during starting.

T10 in fact is a R/Y wire added to ground the 4-pin CIS-E fuel pump relay and turn it on. So add the new wire or use the old relay.

Fuse 17 was reserved for the Knock Box power supply requiring another new wire.
 
#30 ·
I'm working on a carb + knock box + ICM setup right now. I took my knock box apart to sort out this T10 thing.

My box is part number 811 907 397 E. The one with yellow lettering. Cannot guarantee the internals are the same for the other one(s).

T10 is connected directly to the collector of an NPN transistor, a BC337 to be exact. The emitter is connected directly to ground (T3).

This make sense, as MacGruber stated, it drives the low side of the fuel pump relay. I can only assume this is done so the fuel pump does not run all the time when the ignition is on and the engine is not turning. The knock box does this rather than the fuel computer as it's the one with the RPM input.

Time for some assumptions and a hypothesis.

Assuming I am correct in that the fuel pump will be shut off in the absence of RPM. I also don't think these cars prime the fuel system, otherwise there would be no point to the fuel accumulator, the knock box could issue a prime pulse, I'm not sure. This means when you turn the ignition on you will see 12V on T10 through the fuel pump relay coil while the pump is off. While cranking you will still see 12V while the knock box gets synced to the RPM signal, and then probably a bit of a delay in your meter. Once RPM is detected and the transistor is turned on current will flow though the relay and you will then see 0V on T10 just about at the same time you stop cranking. This makes it look like T10 is receiving power during cranking and I bet the origin of the powered T10 myth.

What does this mean for people who connect T10 to 12V? You killed the transistor and it doesn't do anything anymore. Which is fine because if you weren't using T10 as originally wired you don't need it anyways.

Unless of course there are different knock boxes that do different things with T10. In which case this only applies to the E variant. Everyone send me your knock boxes so I can take them apart!
 
#31 · (Edited)
Take a look at the Bentley schematic for Engine Controls - 16-valve Scirocco and notice the +12v wire running FROM the starter (called 15a) - actually 2 wires,
one to the Cold Start Valve.
one to the ECU T24 - a cranking signal.

No starter wire leads to the knock box.

How does the fuel pump prime? My CIS car primes via the large fuel pump relay receiving ignition switch +12v. If the pressure is already high enough the fuel pump doesn't do anything.

 
#32 ·
How does the fuel pump prime?
IIRC the knock box primes the pump at power on for a second, then it shuts the pump off until until the engine starts turning (hall input).


If the pressure is already high enough the fuel pump doesn't do anything.
strange, there is no fuel pressure switch or sensor so I"d say the fuel pump priming is not pressure related..
 
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