PaulN Posted January 17, 2012 Share Posted January 17, 2012 Wondering......why is it necessary to alter the fuel pump timing when removing the EGR and fitting a bypass? Extract from the Disco manual and H@ynes: 300 Tdi ENGINE Type ................................................................................ 2.5 Litre Turbo diesel intercooled Firing order ..................................................................... 1-3-4-2 Injection timing ............................................................... 1,54 mm lift at T.D.C. Injection timing with electronic EGR ............................ 1,40 mm lift at T.D.C. Injection timing with EDC .............................................. 0,45 mm lift at T.D.C. Quote Link to comment Share on other sites More sharing options...
elbekko Posted January 18, 2012 Share Posted January 18, 2012 Interesting. The RAVE does indeed also mention that. Microcat also shows a different part for EGR and non-EGR (in addition to a different one for EDC). I guess they had to do this anyway for the TPS to control the EGR. A possible guess is that for the EGR versions they made them run leaner to meet emissions regulations. Or because there's less clean air entering the engine. Quote Link to comment Share on other sites More sharing options...
PaulN Posted January 19, 2012 Author Share Posted January 19, 2012 Maybe because with no egr the air entering chamber is already hotter than it would be with egr whereupon it lowers the combustion temperatures to reduce Nox emissions? Quote Link to comment Share on other sites More sharing options...
PaulN Posted January 24, 2012 Author Share Posted January 24, 2012 Or.... given the vast number of references to, recommendations through and improvements by removing egr mechanism and fitting a bypass - and the number of guys doing it - why can one find no mention of resetting the fuel timing when one does the 'mod'? Quote Link to comment Share on other sites More sharing options...
sierrafery Posted January 24, 2012 Share Posted January 24, 2012 Maybe because with no egr the air entering chamber is already hotter than it would be with egr whereupon it lowers the combustion temperatures to reduce Nox emissions? Are u sure it's not the other way around? cos IMO without egr only pure air from the filter is coming and with egr is mixed with hot exhaust gas Quote Link to comment Share on other sites More sharing options...
Les Henson Posted January 24, 2012 Share Posted January 24, 2012 If you did alter the timing after removing the EGR - you would never notice the difference in either fuel consumption, or performance. A computer might tell you everything is better, but that's as far as it will go Les. Quote Link to comment Share on other sites More sharing options...
BogMonster Posted January 25, 2012 Share Posted January 25, 2012 Are u sure it's not the other way around? cos IMO without egr only pure air from the filter is coming and with egr is mixed with hot exhaust gas Correct Quote Link to comment Share on other sites More sharing options...
PaulN Posted February 1, 2012 Author Share Posted February 1, 2012 If you did alter the timing after removing the EGR - you would never notice the difference in either fuel consumption, or performance. A computer might tell you everything is better, but that's as far as it will go Les. Fair enough - Except that a 0.5mm to 1mm movement to adv is the only thing that stopped billowing white smoke for me! How close that is in relation to 1.54 from 1.4 I don't know but clearly, it does something..... I do know that timed on pins it is 1.4 having checked it. Now I'd like to get a Dial Guage of my own so I can check and report what sort of movement of the FIP that is. Trouble is I can only find one that works, complete with unions and extension rod, in a set for mega bucks! Just wondered why it's necessary to adjust for EGR or No EGR that's all....guess we'll never know... Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted February 1, 2012 Share Posted February 1, 2012 Can't you just get a 'normal' dial guage and extend the tip? There are normally a few on ebay, both new and used. Wouldn't take much to extend the tip and fabricate a mounting. Are there any extra facilities on the specialist dial guage? Quote Link to comment Share on other sites More sharing options...
PaulN Posted February 1, 2012 Author Share Posted February 1, 2012 Yep - I was thinking about a cheapo off the blag but then not sure how or where to get a fixed extension fited and then how to fasten to pump without proper union - magnets maybe or clamp? Nothing special on the genuine one but just has all the bits to work (ie) extension at correct length and threaded union that's right for the Bosch pump. Basically I suppose you just have to fix the guage in the right place so it can't move (with extension rod into pump running on cam) then (with engine pinned up) turn dial guage to 1.4, unpin pump and rotate to 1.54. Could also start at zero at bottom of cam plate with engine at TDC then rotate to 1.54. Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted February 1, 2012 Share Posted February 1, 2012 Most DTI's have a lug on the back to bolt through for mounting, just make up a bracket that bolts to a nearby bolt so it's held in the right place.... The tip on the DTI normally unscrews so you could remove the tip and fit some pipe or rod to extend it, if you can't make the threads yourself you may be able to bodge it with some araldite ..... You can get a DTI for not too much money .... http://www.rdgtools.co.uk/acatalog/CLOCKS__DIGITAL___MANUAL.html Cheap ones at bottom of page Quote Link to comment Share on other sites More sharing options...
PaulN Posted February 1, 2012 Author Share Posted February 1, 2012 Nice one! - thanks CW! Quote Link to comment Share on other sites More sharing options...
Les Henson Posted February 1, 2012 Share Posted February 1, 2012 You can get mag mounts for DTI's (Ihave one). They are usually a rigid rod and lockable joints that allow the DTi to be set in the right position (the engine block in your case), then locked in place, DTi zeroed, then reading taken over the movement you want to take a measurement of. Les. Quote Link to comment Share on other sites More sharing options...
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