This Idle air control valve (IACV) fits the following part numbers. Also known as air bypass valve, stepper motor or speed control valve. 

BOSCH                         0280 140 515

MAN                             51 13109 0051

PORSCHE                    928 606 161 01

ROLLS-ROYCE             UE 71604

Make	Model	Type	Year	KW	HP	cc
PORSCHE	928	4.9 S,S4	08.86-07.91	235	320	4957
PORSCHE	928	5.0 GT	01.89-07.91	243	330	4957
PORSCHE	928	5.0 S4 CAT	08.86-07.91	235	320	4957
PORSCHE	928	5.4 GTS	05.92-01.95	257	350	5397

Also fits Rolls Royce but we require buyers to confirm the compatibility before the purchase

ROLLS ROYCE CORNICHE II  :             1990 1991 1992

ROLLS ROYCE CORNICHE IV :             1993

ROLLS ROYCE SILVER SPIRIT :           1990 1991 

ROLLS ROYCE SILVER SPUR :            1990 1991