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Re: Full throttle enrichment switch? (LupoVW7)

It sends a signal to the frequency valve on the fuel distributor and increases the rate. It's not much, but it does richen the mixture up a tad.
 

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Re: Full throttle enrichment switch? (LupoVW7)

The full throttle enrichment switch puts the fuel computer into open loop mode, essentially taking the O2 sensor out the circuit. In open loop mode the frequency valve runs a duty cycle of 65%, if your idle mixture is properly adjusted, the system will normally run about a 50% duty cycle in closed loop mode. A small word of warning, if your idle mixture is not properly set, the frequency valve can run more than 65% in closed loop in which case, the full throttle enrichment switch will actually lean out the mixture.
 

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Discussion Starter · #4 ·
Re: Full throttle enrichment switch? (ABA Scirocco)

How about a system that doesn't have an 02 sensor and is missing a full throttle enrichment setup? What will happen with the duty cycle.
 

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Re: Full throttle enrichment switch? (LupoVW7)

quote:[HR][/HR]How about a system that doesn't have an 02 sensor and is missing a full throttle enrichment setup? What will happen with the duty cycle.[HR][/HR]​
As far as I know, there's no way of hooking up an enrichment switch to a CIS-basic system
 

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Discussion Starter · #8 ·
Re: Full throttle enrichment switch? (ABA Scirocco)

My setup is CIS with an RD code engine. The RD from the factory had the CIS-E system. I no longer have an 02 sensor, or a knock sensor setup. In terms of performance would my setup benefit wiring in a full throttle enrichment switch?
 

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Re: Full throttle enrichment switch? (LupoVW7)

If you've got no knock sensor, I'd think you would want to do whatever you can to make sure the thing doesn't lean out up at the top end.
 

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Re: Full throttle enrichment switch? (LupoVW7)

quote:[HR][/HR]My setup is CIS with an RD code engine. The RD from the factory had the CIS-E system. I no longer have an 02 sensor, or a knock sensor setup. In terms of performance would my setup benefit wiring in a full throttle enrichment switch?[HR][/HR]​
The engine will tend too lean out a bit at high rpm under heavy load, exactly when you don't want it to, the enrichment switch help combat this. Running too lean under load can cause pinging. If you tend to push your car hard, I'd consider restoring the CIS-E and knock sensor.
 

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Re: Full throttle enrichment switch? (ABA Scirocco)

Volks,
You will gain from wiring the switch up, but only above 3500-4000 rpm or so. On my Cabby full throttle with the switch would noticeably bog the motor under 4k. To fix this you want to wire in an rpm relay to bridge the ground connection only when engine rpms are above approximately 3500 rpms. The CIS-E setups do this stock...
hope this helps you folks,
regards,
Peter Tong (whose cabby's OXS switch is no longer wired that way)
quote:[HR][/HR]My setup is CIS with an RD code engine. The RD from the factory had the CIS-E system. I no longer have an 02 sensor, or a knock sensor setup. In terms of performance would my setup benefit wiring in a full throttle enrichment switch?
The engine will tend too lean out a bit at high rpm under heavy load, exactly when you don't want it to, the enrichment switch help combat this. Running too lean under load can cause pinging. If you tend to push your car hard, I'd consider restoring the CIS-E and knock sensor.[HR][/HR]​
 

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Re: Full throttle enrichment switch? (Peter Tong)

my enrichment switch is missing... and one of the wires (brown ) is grounded and one is just dangling there... as previous owner put an A2 larger T body and didnt put the enrichment switch on...
if one wire is grounded and the other is not connected to anything, that means i am leaning out on the top end?
i dont think i am leaning out anywhere, since o2 is new, and the car runs pig rich throughout (terrible gas milage)
 

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Re: Full throttle enrichment switch? (cabrio_boy)

If just one wire is grouned, it's not going to do anything. One wire on the switch goes to ground (the one by the pivot) and the other one goes to the frequency valve. If you don't have it connected, I don't think there's any way for the O2 sensor system to go open-loop (unless you disconnect the O2 sensor, which is how your car is setup). I suspect the fact that you're open-loop all the time is one of the reasons you're running rich.
I've got my FTE circuit wired up to a switch on the dash for thhe race car. Once the car is warmed up and I'm out on the track, I flip it on. That way the system runs open-loop all the time when I'm on the track.
 

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Re: Full throttle enrichment switch? (millerwj)

If you have the circuitry for an O2 sensor in place but no O2 sensor installed, the ECU go into "Limp home mode" an open loop mode with a duty cycle of 50%, depending on the adjustment of the air sensor plate this could be lean or rich. As for the FTS wires if the brown wire is grounded nothing happens if the other wire is ground this would put the ECU into 65% open loop mode.
 

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Re: Full throttle enrichment switch? (LupoVW7)

Here is a ?????
My bro's car started to run really rough -- stall, hesitation, no power, etc. When I hold the full throttle switch on (with wire tie) simulating full throttle, the car runs great, but when released it runs like crap. I told him that the computer must be fried ---
what does this mean -- is the car not getting enough gas, ignition, or the computer is not working

OH -- it was my old car -- "86" GTI with CIS-E



[Modified by AkVdub, 8:21 PM 9-2-2002]
 

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Here is a ?????<br>My bro's car started to run really rough -- stall, hesitation, no power, etc. When I hold the full throttle switch on (with wire tie) simulating full throttle, the car runs great, but when released it runs like crap. I told him that the computer must be fried --- <br>what does this mean -- is the car not getting enough gas, ignition, or the computer is not working <IMG NAME="icon" SRC="http://www.vwvortex.com/vwbb/confused.gif" BORDER="0"> <IMG NAME="icon" SRC="http://www.vwvortex.com/vwbb/confused.gif" BORDER="0"> <IMG NAME="icon" SRC="http://www.vwvortex.com/vwbb/confused.gif" BORDER="0"> <p>OH -- it was my old car -- "86" GTI with CIS-E <IMG NAME="icon" SRC="http://www.vwvortex.com/vwbb/rolleyes.gif" BORDER="0"> <BR><BR>
[Modified by AkVdub, 8:21 PM 9-2-2002]
Sorry for restoring this extremely old thread but this is the same issue I am having with my 84 GTI. Runs and revs awesome with full throttle switch depressed. Otherwise it stumbles when I rev it or revs slow. I can replace the O2 sensor no problem but it looks brand new... Any thoughts?
 
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