Power loss after pump seal replacement

[HALLEYBILL]

Hi everybody, Having suffered a diesel leak from the fuel injection pump which had gradually been getting worse I decided that the time was right to replace the two O-ring seals on the pump. I did this job last week and it went surprisingly well mainly due to the threads on this website, thanks guys.

I ran a good battery flat twice trying to restart the engine but to no avail, the juice just was not getting through. I disconnected the pipe from the fuel filter by undoing the large nut on top of the FIP and poured fuel in. Eventually the engine fired up and seemed to be running OK and best of all no leaks.

I went out for a test drive and found that the power from the engine was way down, it felt as though the turbo had packed up or the ECU had gone into a limp home mode. I had a top end of about 35mph and it struggled to pull top gear, preferring third. The engine starts up instantly when the key is turned which rules out most of my guesses as to what it could be.

My problem is that I do emergency call out to life threatened patients for the East Anglian Ambulance Service (First Responder) and it is a bit frustrating when minutes count in saving someone, and the vehicle will only do about 30, it gets called a bit more than a Bongo! Currently it is a toss up whether to use the Bongo or my Ford Model T as the tee tops out at between 35 -40 mph but doesn't go around corners quite so well!!

So, has anyone else experienced this problem in the past when changing seals, or has any advice on what it might be. I tried an Italian tune up along the local dual carriageway but that made no difference.

Any suggestions gratefully received.

[The Great Pretender]

My guess is that you have disturbed a connector or pipe around the IP, there are lots.
Others may be able to offer specific help, good luck.


http://lushprojects.com/bongopartsmk2/c ... 1of02.html

[Northern Bongolow]

it is difficult to see the back side seal----------------is it in place properly, any air gap may allow air into the fuel pump. the seals you have replaced are connected to throttle advance so if these are wrong you may have no pressure rise so no throttle.

did you put back the shims and springs behind the offside/domed seal cover correctly ??.

there is a thin pipe that connects to the top of the fuel pump , it comes from a stub on the air inlet manifold (just to the right of the pump top) is this still there, if yes make sure its clear and that the bit it connects to is clean inside (the diaphragm) on the pump, both of these are part of the throttle advance set up.

[HALLEYBILL]

Thanks for the possibilities, I'll check them out tomorrow in daylight.

The back seal feels as though it is in correct and is not leaking now............

One of my options was to pull off the domed cover and check that the cup is in the right way around, any idea if the engine will run at all with the cup in the wrong way round? I see in a previous thread that the cup is identified and shows which way round it goes in, I'll have to check that before I pull it apart again.

In the meantime I've sold my soul to the devil and bought an old Mondeo to get me about. it feels quite nice to drive a "normal" car after 7 years of Bongo and the Model T!!

[Northern Bongolow]

if I recall correctly the springs go inside the cup so if you have put this the wrong way round it maybe jamming the piston, this moves from the dome cap to the inner plate side (or the other way round) when the throttle is required/pressed.
don't be tempted to push the piston in though to check as there is a vertical peg that locks it, these have been known to come out,


heres a good drawing, thanks to mike for this.
http://homepage.ntlworld.com/mike.gough ... 20Pump.jpg

[HALLEYBILL]

I had another look at the engine yesterday and can see nothing amiss externally such as wires off or pipes unconnected. Engine still starts first turn off the key but way down on power. It picks up and revs OK on the throttle in neutral but lacks oomph on the move.

My next move is to remove the domed cap again and check the orientation of the cup, shims and springs as shown in the post "DIESEL PUMP LEAK" posted on Sat Jun 01 2013 by Bongo boy.

Thanks for your help and guidance with this problem.

[HALLEYBILL]

To continue the saga - I was unable to find anything wrong externally so took the domed cover off again to check the order of the parts. I got the spring and shims out OK but as I removed the collar a small piston dropped into the bowl that was ready to catch all the bits and pieces that slipped between my fingers.

This piston appears to just push back into the hole that it came out. Can it be really that simple as the piston appears to have a number of holes in the side that possibly lines up with an aperture in the bore?

At the present time I still have the cover off and all the parts on the kitchen table. Next step is to replace all the parts and the domed cover once I can decide how it all goes back in.

Once again, any advice gratefully received before I reassemble in what I think is the correct order.

[hijimhere]

daft I know but is the air intake clear - any restriction will drop your power as I found when I tyed to store a plastic bottle for topping up in the gap beside the air intake - I found it just as the AA man arrived - yes he put it on his "report" thankfully he left out the words " this idiot put" lol

[Northern Bongolow]

if you look at the drawing in the link above it shows the peg that goes through the hole in the piston you refer too. .