[hepkat63]

Originally Posted by ischmitz

For what it's worth: If a chip (EPROM) was put in wrong (even one bent or broken pin) or damaged in the process the car would not start at all. And similarly, if any content inside the chip was bad the car would not start at all. It's a very black & white picture.

So the only possible explanations are:

- the specific chip is not compatible with your setup
- you have something else not working properly (vacuum leak, sensors, fuel pressure, etc.)

The simple test is to swap back to the stock chip to confirm nothing else coincide with you putting the SW chip in. The "learning" is an adaptation of the volumetric efficiency of the engine at idle. This function relies on a perfectly working O2 sensor and takes a fully warmed up engine to drive around for some time. After that the mixture is adjusted ever so slightly with a trim value to maintain a stoichiometric mixture at idle (as seen by the O2 sensor).

The 964 Motronic chip has multiple maps that are chosen based on the personality jumpers on the DME harness. These jumpers are set based on region, manual vs. tip and O2 sensor Yes/No. Some aftermarket chips ignore these jumpers altogether by bending all vectors inside to the one modified map set while other chips have all individual maps changed.

There are differences between the manual map and the Tiptronic map to account for the specific behavior of an automatic transmission (torque converter is dragging the engine instead of a clutch completely unloading the engine). If these jumpers are ignored in an aftermarket chip drivability might suffer.

Ingo

wow! thank you !