Hi all, you may remember that my new-to-me 16v has problems starting when hot, and likes to stall when hot and coming to a stop. I am trying to diagnose this myself, as I don't have a local mechanic who can work on it for me in any near time frame.

This weekend I have tried to check the duty cycle, as I know the previous owner was playing with the idle mixture screw. I have a meter with duty cycle and these were my readings:

- Car off, ignition on. 50.6%
- Car idling, cold - 50.6%
- Car idling - hot - 95%

Adjustments of the mixture screw do not change this 95%.

It is my understanding that these readings (50%, and calling 95% 100% for fault code purposes) point to a faulty lambda sensor. With that in mind, I set out to read the voltage from the lambda sensor directly. I plugged in to the sensor under the passenger seat with a home-made harness. I got the following readings.

- Start the car (already warm) - 0.48v
- As the car idles, it climbed slowly to 0.78v where it stays steady
- If I give the car gas, it drops in a linear fashion to ~0.7v, then climbs back up to 0.78v at idle.

I am not sure if this indicates a bad lambda sensor or not.

Any suggestions on what I should do next based on these readings sure would be appreciated.

Thank you.