I found the Ebay auction pictures very interesting!...

Closed Loop BLM's above 128 are lean.

Closed Loop BLM's below 128 are rich.

Most TBI computers will "lock" the BLM's @ 128 until closed loop.

The acceptable BLM "averages" range is between...

My 1227747 tuning experience has shown me to keep the BPW "window" to +/- 10% of the stock setting. Typically the 1227747 5.7 Liter TBI has BPW of 135, so a window of +/- 10% is a BPW between 121.5...

A data log can provide useful information, even when the engine is running poorly.
Base Pulse Width (BPW) is an important parameter.

dave w

17354

17355

Are you setup to reprogram the 1227747 PROM chip?

dave w