93 starts won't Idle

[ss#4]

Okay here is the last update for tonight.

I pulled the PCM connector and pinched the terminal tight to where the PCM pin should spread the pin open during installation. Basically the best thing I can do to ensure connection.

And ....... the same thing no Sensor 1 O2 output through the scan tool.

ARGH!!!!!

Let me know what the thoughts are on a new PCM.
IS the only Tauras out there that has had this type of problem????????

[shorod]

The O2 sensor actually generates a voltage based on the difference between the amount of oxygen in the reference air (outside the exhaust) and the oxygen in the exhaust stream. My understanding is it does not need a reference voltage. The sensor can generate as high as 1 Vdc. The 12Vdc supply voltage you are seeing is only for the sensor heater. An oxygen sensor is only accurate once it gets up to operating temperature. Early single wire sensors did not give readings for the first few minutes the car was running. This was one of the reasons the early computers would start out operating in "open loop" until the coolant temperature got up to some set temperature. At that time, the computer would transition to "closed loop" and begin to use sensor feedback to control air/fuel ratios and other parameters.

Since you are seeing a voltage at the PCM, but the scan tool is not reporting it, that does make the PCM suspect. One thing you should try is to disconnect the rear O2 sensor and see if the voltage between pin 44 and pin 46 remains at 0.9 Vdc. If so, the voltage you are seeing is coming from the PCM rather than from the O2 sensor. That again would lead to a suspect PCM. If the voltage drops to zero, and the sensor is actually putting out a constant 0.9 V, you either have a bad sensor or a VERY rich mixture on the rear bank of cylinders.

As far as picking up a used PCM from a scrap yard, I wouldn't be too concerned about that, depending on the price difference from a reman unit. Ford PCMs have been rather robust.

-Rod

[ss#4]

Still searching for the problem.. I picked up a "new" computer from the yard plugged it in and it still does the samething. Still 0.00v output on the scan tool. I also replaced the coolant temp sensor and still no change.

as a side note, This thing has also generated a slight whistle (sounds like a vacuum leak) at cracked throttle, that is loud enough to clearly hear going down the road. I used a hose to try to pin point the sound and it is around the #4 injector. So I pulled the intake off and replaced the orings at the manifold. No change. I looked the upper and lower manifold over closely but I don't see any cracks and I am positive the new lower intake gasket is sealing. I have sprayed brake klean, carb cleaner and propane and can't pinpoint the leak any better.

Anyone else had any whistling issues like this?

This thing sure has me guessing at this point????????????

[shorod]

Wow, I'm going to be very interested to learn what you finally find to get this car fixed! Your car has some strange issues!

-Rod