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Bosch pump timing (JX)

Posted: 02 May 2012, 13:32
by Evsi
I know this is going to be a proper blonde moment, but can someone help me with a brain blank?

Looking up on the correct pump timing routine for the Bosch pump, it states that with the engine timed to TDC, insert the dti into the rear of the pump with say 2 mm pre-load and then rotate the engine anti-clockwise a small amount before zeroing the dti. Now my brain (probably broken with all the beer...) is telling me that unless you have a set degree of anti-clockwise rotation before zeroing, then you will always have a different reading when it gets back to TDC?? :?

My head hurts from thinking about it now.......

Re: Bosch pump timing (JX)

Posted: 02 May 2012, 14:38
by Evsi
Evsi wrote:I know this is going to be a proper blonde moment, but can someone help me with a brain blank?

Looking up on the correct pump timing routine for the Bosch pump, it states that with the engine timed to TDC, insert the dti into the rear of the pump with say 2 mm pre-load and then rotate the engine anti-clockwise a small amount before zeroing the dti. Now my brain (probably broken with all the beer...) is telling me that unless you have a set degree of anti-clockwise rotation before zeroing, then you will always have a different reading when it gets back to TDC?? :?

My head hurts from thinking about it now.......

Actually, i think i've got it. I suppose you need to rotate it ant-clockwise until it reaches the end of it's last cycle, not "a small amount".

Re: Bosch pump timing (JX)

Posted: 02 May 2012, 19:51
by dave friday
Evening, put a bit of preload on the DTI, turn the engine to top dead center [clockwise] then turn back [anticlockwise] until the DTI stops moving,zero the DTI then back clockwise to top dead centre,the reading now is the amount of advance[.8 to .9].
Took me ages to get it right in my head!!!.
Good luck.

Re: Bosch pump timing (JX)

Posted: 03 May 2012, 08:40
by Evsi
Cheers Dave,

I think the thing that was confusing me was how far to turn the engine anti-clockwise, because the manual i read didn't state to turn it until the dti stopped moving. Clear as mud now :ok

Re: Bosch pump timing (JX)

Posted: 03 May 2012, 14:51
by dave friday
It does get clearer!!!.