The easiest way to distinguish between the early Weber-Marelli management systems is by the colour of the fuel mixture trim screw in the box. On the front face of the management box, where the large wiring loom plug fits, is a recessed hole, with a small plastic screw visible.
• The early hatchback systems have a yellow screw (L1);
• Four door cars have a white screw (L6). Also, the Weber-Marelli Level 6 systems have a mounting flange on their front face to fix them into the car.
• The Level 8 & P8 systems do not have a mounting flange; the sides of the box are smooth. Only the very early P8 systems were fitted with a mixture trim screw, but as an extra check, the Level 8 systems have a red or green sticker on one of the covers, this will have WD48.08 printed on it. P8 systems have a white sticker, and this will read IAW48/P8.