Have been having an annoying little problem with my bus the last couple of weeks in that from a standing start the engine revs upto 1500 normally but then goes really flat,ejects big plume of black smoke,until it gets to 1900-2000 revs when the turbo light comes on
then starts to accelerate normally again with no smoke.
I thought maybe the fuel filter was blocked so duly changed it this weekend but to no avail-still same trouble. While looking over engine for anything out of place I noticed on top of the injection pump at the front there is a dome shaped housing with an allen screw in the centre and a vacuum pipe coming off it,the said pipe looked perished at the end so I thought I'd change it,but on trying to get the pipe off it split completely - hey presto acceleration back to normal with no smoking. Pipe on - no power,Pipe off - no problems ??????

Can anyone enlighten me into what the housing contains and is it essential as everything seems to work fine with it disconnected - i was thinking maybe there is a diaphragm underneath it which may have split.

Any help greatly received.


Pete
- (#7643) pete, 10 Mar 03

Something iffy in your pump. that's the on'boost enrichment device. Adds fuel when the turbo boosts. Now the odd thing is that excess fuel shouldn't make the engine lose power. There's a diaphragm and spring under it. Is your airfilter clean?

- (#7644) david miller, 11 Mar 03

Thanks for the description David.

I replaced the air filter only six months ago and it still looks ok but i tried driving a short distance with it removed,not a good idea i know-but wanted to prove to myself that air filter was not problem,and it did not make any difference.The wife commented that the fuel consumption seems a tad excessive now-could this have anything to do with the enrichment device being disconnected?
- (#7645) pete, 11 Mar 03

no, that should only make the engine flat, and if anything improve the mpgs...

- (#7646) david miller, 12 Mar 03