I have a 1985 GLH converted to T2 GLHS specs and I have been experiencing a lean condition when I start the car cold. When I start it cold, it will go lean on the wideband, sputter, and eventually die. To troubleshoot, I back probed the coolant signal wire at the LM to get voltage readings. Here is what I found:
- When the car has been sitting overnight, the coolant signal wire at the LM reads 2.5V with the ignition key on (not running)
- When I start the car, the voltage on the coolant signal wire will begin to drop. After about 30 seconds or so of running, it will drop below 2V.
- After the car runs for about 1-2 minutes, the coolant voltage jumps to 3.8V which is the voltage I would expect to see given the temperature of the coolant at the time.