MB used either 1 large pump or 2 smaller pumps on cars from 1986 - 1993 with CIS fuel systems. 1 small pump doesn't have the needed volume to run car at higher RPM's. With 2 pump system their is less AMP draw & higher out-put than the 1 larger pump. The car should run IF the hoses are removed from the BAD pump. System pressure is around 90psi.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator