TECHNICAL NEWSLETTER 07-09-05
ROVER 300 TDI ENGINE FUEL INJECTION PUMP Problem:
This engine came to us partially dismantled after an overheat. As it would turn out later, the drive hub had been removed from the injection pump during the mechanic’s strip down, and caused great pain and suffering later.
Come time to assemble the engine, no one had the timing or even the timing order for this rotary pump.
For future reference the pump is set at 1.5mm (0.059″) with #1 at TDC. The pump pipes run – #1 at the lower corner closest to the block #3 lower and furthest from the block. #4 at the top but furthest from the block #2 at the top closest to the block. Firing order is 1,3,4,2.
At start up it faltered and the mechanic then called for help. Injection timing was on the wrong cylinder even though we went by the procedure.
Cause:
The pump drive is hidden behind what looks like a conventional chain case containing a chain drive in an oil environment.
Not so.
This is a toothed belt drive some 2 1/2 hours away to remove the radiator, balancer and accessories and finally the cover. There we find a strong toothed belt and the usual idler and tensioner driving both the camshaft and the rotary pump. The belt drives onto a pressed steel radially adjustable belt “gear” for both the camshaft and pump drives. The pump drive is a hub mounted via a TAPERED nose and nut onto the rotary pump shaft. Without a key drive, it is extremely difficult to regain the setting done at the factory, once the taper has been broken; as our “motor” mechanic had done. The factory method is by securing the flywheel and the rotary pump with two dowels and, in this position, to then fit the drive belt. Unfortunately, we had the tapered hub firing on another cylinder.
Cure:
Difficult. Two men fought this unfriendly mechanism for another two hours before arriving at a compromise whereby the timing was re-established. The engine now runs as would be expected. Definitely DO NOT allow the mechanics to remove the hub from the pump. It is a common job for the tow truck operators to flat top these vehicles from the mechanics to the local pump room for help in timing after changing a belt_
For further assistance contact Scott James at Engine Action Nth Melbourne.