All this recent talk about F.I. got me to thinking (Caution, this condition can lead to dangerous situations). I just thought I should check out some things on the still new to me Yellow Rabbit. Also, I was down at Sebring last weekend attending my second school and I the engine just wasn't pulling as hard as I thought it should in third gear, might have been the 110 heat index and the car original came from the Northeast.

This is what I found...

Control pressure is 49 hot and system pressure is 74, the WOT switch is zipped tied closed, no thermo switch, not sure about the thermo switch wiring if they are open or closed so I will just assume they are where they should be. When I go and check the duty cycle I can't get a reading at the "duty cycle plug".

Question 1: Is it common practice in the Hot VW racing ranks to bypass the WOT switch, thermo switch? Does this pretty much take the OX sensor and freq valve out of the equation and you are just left with a purely mechanical F.I.? Probably not a bad thing. And leads me to Question 2.

Question 2: Is there another way to check the air/fuel mixture without the duty cycle? I'm thinking I have seen where you can take a direct ready off of the OX sensor. Something in the neighborhood of 400-500 mili-volts sound about right? Maybe do this check at 4000 RPM? Or is there somewhere else to do the duty cycle test, at the "brain box"?

I am really liking the idea of taking the car to the dyno and getting the air/fuel and timing checked under load. Probably a good investment of time and money.

P.S. I'm signed off to go racing, so look for me at CMP on 9/16, I'll be the Yellow Rabbit with the big 'X'!

Thanks,
JimW
#74 Wraycer Wrabbit