Well, I honestly feel bad about hi-jacking the OP's Thread. But, seems he must have got his question answered. So, I'd rather not start another Thread.
So, here is what I am dealing with.
I did a TB job on this car at 120k miles and set the T Value at 0.0. ('04 BEW) It started just fine with no complaints from the owner. Well, over the last 6 months it has become a hard starter. The battery spins the engine just fine, so, that is not the issue. Starter seems fine too. The odometer is now at 152k miles (32k on the belt).
So, I checked the T value and it was at -1.5. Also, there was a DTC for the Temp Sensor. I saved and cleared the code. After numerous starts that code did not come back. ............ now, after several days putting this thing off, I'm back at again.
I've set the T value in several spots between 1.0 to 3.9 but still getting hard starts.
Then, bam, the Temp reading on the last start shows up at -19c and the engine was crackling like it was a very cold morning (2.4 T value). Then, all of a sudden the Temp reading jumped to 83.1c. So, obviously, I need to install a new Temp Sensor.
To adjust the T value. Using a Sharpie, I lightly made a mark for reference. It is fairly easy to move the Cam bolt to make adjustments... but, as has been stated, it doesn't take much to change the T value considerably.
Anyway, is it possible that the faulty Temp Sensor is affecting the "real" T value? Or, once I change the Temp Sensor, should I venture into the negative numbers? 0.0, 1.0, 2.2, 3.4 & 3.9 advanced never helped at all.