I would remove injectors and bench test. While out I would check compression. If all cylinders were above 300psi I would worry next about the pump. The first thing I would do to it is replace the pump element check valve to cylinder seals brass ring part# 000 074 17 59. Unfortunately I think you have the pump with external fuel correction. This can be determined by whether there are two 13mm wrench, 8mm nuts holding (and adjusting the pump cylinder) right blow the injection line. This adjustment is only for pump shops so they will have to replace the seals and probably the element check valves. To solve the problem. The early mechanical (as oposed to pnuematic) pumps had three updates to the check valve design. The problem is that a portion of the column of fuel in the line leaks back into the pump causing the first pump pulses to refill the line before proper injection can occur. As the leakage always varies cyl to cyl the engine starts running one the cylinders one or more at a time.



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Steve Brotherton
Owner 24 bay BSC
Bosch Master, ASE master L1
26 years MB technician