Injection pump settings - citroen bx

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Mon 3 Nov 2003 09:31
Injection pump settings - citroen bx - Andrew Citroen
I recently had a replacement engine fitted in my 1991 BX TGD.

The engine was a 162 - a somewhat earlier type to the DB8/6 fitted originally. It came with a CAV injector pump and its existing injectors but ran very badly. The garage replaced it and the injectors with my original engine\'s Bosch pump and injectors and everything runs very smoothly - BUT the engine is not as lively and not as fast.

Technical data indicates the later 1905 cc diesal was about 5 hp stronger. Should I expect a fall off in performance because of this - should the pump be tuned?

A final point, 3 injectors are leaking - would this reduce power significantly?
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Mon 3 Nov 2003 12:04
Injection pump settings - citroen bx - M.M
Andrew,

Oh dear...several issues here.

The later engines were indeed almost 10% up on power so you could notice that difference on fitting an earlier one.

To gain this power they changed the camshaft/valve timing and the inlet valve sizes...at the very least. Both the injectors and diesel pump were also of a different spec. So on the face of it you need to keep the engines and fuel gear matched between engine types. So it may run better with your original gear on the old engine, but it may never run perfectly.

Lastly you've fitted an engine that is at least four years older than the one you took out, and you say it ran poorly as fitted with its own injector gear. So perhaps it is already quite worn and that is another reason for the lowere performance.

And never forget the fact our impressions are not always right, we sometimes get a false view of better/worse after work/expenditure.

Information on the source of the replacement engine and if you heard it running before purchase might help.

M.M
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Mon 3 Nov 2003 14:28
Injection pump settings - citroen bx - Andrew Citroen
Thanks v much for your advice - it more or less confirms what I thought. Do you think a tune up would help and do the leaking injectors reduce performance significantly?
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Mon 3 Nov 2003 15:12
Injection pump settings - citroen bx - M.M
Andrew,

Whatever your decision about the overall condition of the engine those leaky injectors do need sorting, I assume you mean that the small bore "leak-off" pipes are losing diesel where they join the injector??

Frankly there is not much to "tune-up" on a diesel. A new air/fuel filter would be a good starting point and the only other thing really is diesel pump timing. There is only one setting for this and it is the right setting...and we'd hope that was how the guys who fitted it have set it!

Do you think the engine sounds "too" smooth? Sometimes if the pump is set a bit retarded the normal diesel knock is muted...and the performance drops off.

Good luck.

M.M
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