The Bosch EFEP 385A
ENTERING The MODERN AGE
The Bosch EFEP 385A was the next iteration in Bosch's line of benches and is currently represented by two models in our pump shop. With a number of updates to ease usability, it's major feature is a moveable cylinder viewing area that allows access to the pump from both sides of the bench, allowing greater efficiency and less movement required by the technician during service.
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Though the underlying mechanics of the bench's operation remain largely unchanged, a streamlined design and fully encased body give the EFEP 385A a decidedly more modern aesthetic from its predecessors, while minor updates to the layout improve usability for the technician.
The Bosch EFEP 385A was constructed with a cast aluminum swivel-frame featuring a tiltable measuring glass holder atop a sheet metal body with panels welded together before being fitted over the transmission and inner workings. Despite its earlier date, the high-quality construction, sound deadening materials and lower horsepower actually made the EFEP 385A quieter than its successors and we've found that it's the perfect option for gasoline fuel injection pumps like those found in the W113 SL-Class despite its age.
The Two Plunger Bosch EFEP 385A
Our dedicated TWO plunger bench
This 385A is same model as our other 385As, but has been specifically set up for 2-plunger Bosch fuel injection pumps commonly seen in vehicles like the W128 220SE, W111 220SEb, and the W112 300SE.
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While the pump itself only has 2-plungers the vehicles still have six injectors, requiring each plunger to feed fuel to three injectors at one time. Through some special modifications including a mounted rack, we can easily exchange injectors to test working condition and rearrange the order in an attempt to equalize fuel distribution.
While these pumps are more difficult to calibrate and allow less control throughout the process, our 2-plunger bench setup ensures that we will detect performance issues while providing a simple and relatively quick method of testing different injectors, injector lineups, or change focus to the internal workings of the pump if needed.
