This weekend I will be checking top end for unmetered air and plan on replacing the rubber tubes, fuel injector o-rings, Intake seals at heads.
I also will replace the fuel pressure regulator. (It's reading high)
I have an o2 sensor on its way and have a head temp sensor ready if needed.
I'll have acess to the hammer next week and hopefully the dignostics plug in hand and installed by then.
We are on the same page with the By-pass on the Air Meter it allows unmetered air to go arround the flap in the sensor. I'm 99% sure that the way mine is plumbed, the ICV allowes "METERED" air to By pass the throttle plate, but the ECU controls the opening depending on load and other variables to keep the idle speed steady. It's my understanding that the two are seperate.
What I hope to do is to find a way to adjust the mixture without the DME doing any compensation whle I'm making the adjustment.
I think the '84-'89 Carerra has a test plug that you install a jumper that effectivly disables DME compensation during the adjustment only.
I assume the O2 sensor is unplugged while doing this.
On the 964, I don't know what, if any provision is made for this. Maybe can be done with the code plug.
There is another 3 pin connector (Black Boshe type) in the engine harness under the seat with nothing plugged into it. It is right next to the white code plug. Is this test port? My code plug HAD no jumpers which I understand is for an a no-cat car. I installed a jumper the other day to set it for a cat car. Center terminal to positive terminal.
Hoe is this connected to the O2 sensor if at all? Maybe it switches something in the DME?
The Chip in the DME is a GIAC chip. I plan on replacing it with a stock chip.
Do the aftermarket chips effect the "adaptation" mode, or is that done somewhere else in the DME?
Thanks for all the help!
