fuel lines / pump / power down

[maxgreenwood]

I have a problem with my TZD turbo estate in that power is down, i can feel the turbo but i reckon i've got about 50% of the power i should have. The car also lurches/judders on acceleration and decceleartion especially between 1-2000 rpm. The lower engine mounting is worn and could be contributing to this, but a couple of you have suggested a problem with the fuel feed and this was confirmed by a citroen garage here when i got the car in to be thoroughly checked out. Power loss confirmed. Among many other things needing doing like a ball joint, front suspension bushes, little leaks, the garage reckoned the fuel pump (bosch) needs looking at and may have been detuned to pass the MOT emissions test. Only get smoke on startup. He also noted the diesel fuel lines are badly corroded.. I'm thinking maybe the pipes are restricting the flow or could be collapsed or could there be a build up of rust somewhere?

What would be my first point of diagnosis? should i try and tweak max fuel settings etc on pump 1st or check for corrosion internally, replacing the lines etc?

[jeremy]

On a diesel BX the only fuel lift pump is in the injection pump which means that all the pipework going back to the tank is under suction and will admit air while not loosing fuel.

Diesels run at extremely high pressure (last section - pump to injectors) and any air in the fuel makes it impossible for the necessary injection pressure to be obtained. This results in bad starting, smoke and misfiring in various combinations.

So to function properly all the pipework must be in good order. The steel pipes go porous before leaking - and can be obtained from Citroen cheaply.

A useful tip is to replace the last pipe to the injection pump with clear plastic so that you can see when you've got the air out of the system.

If your car has a Bosch pump the injector leakoff pipes must be in good order - as they can admit air to the supply side. They can be replaced with small bore fuel tube cut to length. the end cap must be replaced as well. Roto-diesel pumped engines just leak and smell - the pipes don't affect the running.

[DLM]

Step by step is best in any diagnosis but if the pipes are looking bad then it's a pretty sure bet they are a weak link. However, I rarely replace anything without having satisfied myself of exactly what the problem is.

Suitable clear plastic pipe immediately to/from the pump will give a good idea of any air problem.

By the way, I'd advise you get the garage to replace the balljoint unless you're exceptionally well tooled-up - it's an off-car job from all I've heard and I've had no end of niggling problems with them in the course of other jobs on BX front suspension.

[DavidRutherford]

I'd advise you get the garage to replace the balljoint unless you're exceptionally well tooled-up - it's an off-car job from all I've heard and I've had no end of niggling problems with them in the course of other jobs on BX front suspension.

I've done two now. One on the car and the other off. Although it is definitely easier to do with the hub off the car, it's probably slightly quicker to do on the car. The trick in both cases is a big punch and an even bigger hammer. Belt the old one out HARD and it should move. If you don't, you'll just bugger it into place. Alternatively a BIG pair of stilsons and a length of tube as an extension works quite well too.

Either way, the "special tool" is a load of rubbish and completely un-necessary.

[cauchoiskev]

The trick is : don't undo the bottom nut until you have loosened the ball joint. That way, it's a very easy job.

http://bxclub.co.uk/forum/viewtopic.php ... ball+joint

[DLM]

Thanks for the reminder - BX Balljoints and I have an uneasy relationship at the best of times. I did follow the French link on the thread - that BX's lower-arm area was the filthiest I've EVER seen. No rust problems but.....