My Bosch injection pump ceased to work on my 1988 Astra estate car and I have obtained a replacemt which I am assured was working when dismantled from a similar mode,l prior to scrappage.

The problem that I have is that I have never worked on a Vauxhall/Bedford diesel before and am working on memory from Ford diesel vehicles of the same type of period. I tend to remember that after aligning the timing marks on the pump sprocket and timing cover which I have done, I need to set the pistons at TDC before engaging in any further dismantlement of the pump. On the Ford models there is a screw plug where one can insert a pin in order to turn the engine until TDC is attained.

On my Vauxhall, there doesn't appear to be any screw plug to undo in order to insert a pin. I would be grateful for any advice as to where this plug might be, or any alternative suggestions as to how I might attain TDC with my pistons before continuing to remove my old pump. I'm presuming that I do need to accomplish this task, as with the Ford models, prior to any further removal procedures.

I thank you in advance for any assistance you may be able to afford me in this matter.