Diesel Pump Problem

[Ian]

Posted on behalf of member Bob from Reading:

Hi, I'm after some help please.

I have a 95 Bongo 2.5 diesel. It starts fine, the cold idle is fine, a little lumpy maybe, when it gets hot it hunts and cuts out. If I try to rev. it hot or cold there is a great deal of white smoke and it cuts out on occasion. Pumping the primer improves things.

I'm a car mechanic and know a great deal about high pressure diesel injection but very little about the indirect injection low pressure system. (As I've just discovered). Here's what I've tried:

Replaced the fuel filter, no change, then ran the engine from a can of diesel through a primer bulb and clear hose straight to the pump, no change.
The EML flashes when I try to rev the engine, so I tried to read the codes, but there is no connector for the 'ten' pin to earth out.
As there weren't many codes listed I thought I'd check what they were, so I typed different codes into the website linked, (2 digit codes) but no info was returned, just what I'd typed in confirmed.
I noticed a leak on the engine side of the pump, the repair method was shown on the web page so I carried this out, no change.
I've removed the banjo bolt from the inlet pipe on the pump hoping to find a gauze filter or such like, also removed the bolt at the rear of the pump where the DTI gauge is installed for timing, all look clear and clean. I don't have the tooling to check pump timing so not checked.
I've had the engine running and loosened 3 of the 4 pipes to the injectors until a light spray is seen (can't get a spanner on the 4th easily) the engine continued running with no significant change, but I suspect I'd only loosened them enough to check for the presence of fuel.

I'd had this fault once before, from a cold start, but It cleared itself after the engine had warmed, this leads me to the conclusion right or wrong it's not timing. Numbers on the pump are WL04-13-800C. 104740-0694. Any help in diagnosing would be greatly appreciated. Have attached a photo of my diag socket, advise on how to get and decipher the codes would be great too

[lazyb5]

Cant take the credit for this as Ady (Northern Bongolow) told me, but on the top of the diesel pump is a round diaphragm chamber which has a piston in it. This over time accumulates dirt and muck and the advance may become stuck on. Just dismantle and clean out then reassemble, also make sure the pipe is attached to the inlet. This worked great for me.

[Northern Bongolow]

did you find the banjo filter, from your description of what you did you dont say, it is quite deep inside the pump so you have to dig it out, i use cotton buds to lift it out. even if they look clean from above lift it out as they can get like a hair dressers plug hole with dangly bits hanging into the pump. some do throw them away. .

the part mentioned above is shown on the link below.
the diagram isnt accurate though it shows the fuel banjo going in from the side when it goes in vertically. look for the vac pipe from the inlet manifold elbow it enters the fuel pump top, this vac should lift the diaphragm in the pump top, this pipe and diaphragm can get full of crud.
it maybe an idea to remove the fuel cut off switch to check its operating and that the seal is ok too, they can get crudded up and partially stop working.

http://lushprojects.com/bongopartsmk2/c ... mgno=.html

[Simon Jones]

I'd be tempted to call Gerry or Fred at Discount Trucks in Newbury and get them to advise / take a look as very close to Reading.

Don't recall seeing a dedicated EML on the older Bongos although he could be referring to the glowplug light. More info on the diagnostic connector: http://www.philmcfadden.co.uk/MazdaDiagnosticBox.htm

[jimmo62]

If you have an automatic, you use the TAT pin to get the codes (not sure why but this gives you any engine codes as well as the transmission codes) - may be worth trying that?