# wot switch questions



## volkshead83 (Feb 8, 2014)

Working on 83 gti 
I have a couple questions.
1st the wot switch. What is it used for. Enriching the fuel at higher rpms?
2nd when at idle and switch depressed is it suppost to act like it dies or no. Asking becuase a while ago I depressed it and I believe it tryed but cant really remember.
3rd if the switch isnt connected is it fine to be running at higher rpms? Or constantly depressed?
My throttle had to be replaced and had to use one with out a switch so thats my concern.


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## nbvwfan (Aug 15, 2007)

To answer some of the question.
Yes, the WOT enriches during full (~75%+) throttle opening and abve ~1500RPM 
The fuel cutoff operates at 1500 and above RPM, to save fuel while decelerating/coasting. 
If your RPM drops below 1500, the the Hall/Tach signal tells the ECU to resume fueling.
If you manually operate it when the engine is above ~1500 RPM it will sound like the engine is stalling, that is until the RPM falls below then it picks back up.
You can run without either, the only impact may be in some economy and some top end, and the idle may surge and hunt a bit, since you are running your system almost entirely from the mechanical side of operation.

Buy this book  book if you want to know about the various designs of CIS, or download the K-Jetronic service manual


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## volkshead83 (Feb 8, 2014)

Ok thanks ive thought about making a harness and mount a switch inside the car for the moment tell I can get a new throttle body


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## kwak (Apr 7, 2005)

nbvwfan said:


> Yes, the WOT enriches during full (~75%+) throttle opening and abve ~1500RPM
> ...
> You can run without either, the only impact may be in some economy and some top end, and the idle may surge and hunt a bit, since you are running your system almost entirely from the mechanical side of operation.


I can only speak for an 87 GTI 16V throttle body, not an 83 GTI throttle body. The WOT switch activates more like 90% throttle opening. The difference between WOT activated and not activated is almost no change in the amount of air going through the throttle body. THE DIFFERENCE between the two scenarios is this: 

Whether you have CIS-E like my car or the oxygen sensor control unit like on your car, when the WOT is not pressed the computer is always trying to keep the mixture at stoichiometric. This mixture does not produce the most power. You can drive all the time on this mixture. I have been driving my GTI for more than 10 years without ever going to WOT. The mountain roads I go play on are quite fun without ever going to WOT.

When the WOT is pressed, the computer stops using the oxygen sensor to adjust the mixture, and instead reverts to a fixed amount of mixture enrichment on top of the default mechanical enrichment. If you want to drive using WOT, or you want to drag race another 83 GTI and at least stay even with him, or you want to go to the dyno and post a big number, then you need to have a WOT switch on your throttle body.



volkshead83 said:


> Ok thanks ive thought about making a harness and mount a switch inside the car for the moment tell I can get a new throttle body


You could pretend it is the NOS button.


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## volkshead83 (Feb 8, 2014)

It has the single one on top of the tb. It has an incredible engine build. Im wanting to use for hill climb and a weekend fun car. I havent been able to find anything regarding voltage readings at the connector and or ohm readings. Anyone know of any?


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## kwak (Apr 7, 2005)

You'll want WOT enrichment then.

According to the wiring diagram in the Haynes manual, for the 83 GTI, the switch is sync to ground, meaning - the brown/red wire goes to pin 7 of the oxygen sensor control unit, and the other wire goes to ground.


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## nbvwfan (Aug 15, 2007)

kwak said:


> You'll want WOT enrichment then.
> 
> According to the wiring diagram in the Haynes manual, for the 83 GTI, the switch is sync to ground, meaning - the brown/red wire goes to pin 7 of the oxygen sensor control unit, and the other wire goes to ground.


I agree with the ^
If you have a built motor you ought to get the switch or come up with one of your own making. No sense going lean when the engine pulls more than the plate/meter is calibrated to deliver.

As for my earlier input, I apologize if the ~% was off, I was going more based on the theory I could recall and did not pull it from a textbook.

:thumbup:


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## volkshead83 (Feb 8, 2014)

I bridged the two connectors and now shes running smooth as a hungry *** pig. I should of done this sooner


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## kwak (Apr 7, 2005)

If you add a toggle switch inside the car you can switch between economy and race. With the WOT switch active the whole time you are no longer using the oxygen sensor for a clean burn.


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## volkshead83 (Feb 8, 2014)

True. I do also need to get a new o2 sensor for my wideband controller to monitor my a/f it seems as if it is getting just alittle to much fuel with it bridged.


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## volkshead83 (Feb 8, 2014)

Well I wont be doing the switch like planed out this weekend do to having surgery on my right forearm. So once it gets healed enough to do anything thats the first thing im going to be doing.


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## volkshead83 (Feb 8, 2014)

I said screw it and did it anyways. Works and looks beautiful. Will upload pictures shortly.


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## volkshead83 (Feb 8, 2014)

All new wire with a complete shrink wrap end to end for a cleaner slim look.
Ecu harness
https://www.dropbox.com/sc/nc27vewrll6hesn/AABJ60GAqsiNsfGSwjWC2qzra
Main engine harness
https://www.dropbox.com/sc/v61nraquh13jwjj/AABVJn_aJxw5QTU8ilMoz630a


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## volkshead83 (Feb 8, 2014)

I had a bit of a few issues with the car. Had to adjust my wur and replace the fuel filter. And now need to source a fuel accumulator or bypass it.
I know that bypassing it can do alittle bit of vapor lock and hot start loping at idle due to the pump surge, ive been digging up enough research to figure out weather or not I want to go that route.


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