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Rythmic Beat For Doctor Diesel

Posted: 21 Mar 2010
by Bx Bandit
Got a minor issue with the TD. Once she's fully up to running temp, she'll develop a mild rythmic beat akin to a small misfire. Roughly, it's two 'beats' per second at idle but doesn't occur on any level of the load lever being open.

I'm guessing injector, but does that mean it's tired and useless or just needs re-calibrating?

Re: Rythmic Beat For Doctor Diesel

Posted: 21 Mar 2010
by docchevron132
mine does that, runs like a bag of spanners at idle actually..

Likely to be an injector with a piss poor spray pattern, or weeping nozzle..

Re: Rythmic Beat For Doctor Diesel

Posted: 21 Mar 2010
by Bx Bandit
Weeping Nozzle? Enough of the personal stuff!

That would make sense, in that it doesn't happen when cold I guess. They are all clean inside but maybe the spring are a tad tired

Re: Rythmic Beat For Doctor Diesel

Posted: 23 Apr 2010
by David
how fast above idle do you have to raise the revs for the misfire to dissappear?

Re: Rythmic Beat For Doctor Diesel

Posted: 24 Apr 2010
by docchevron132
just had another thought actually, a tight tappet would do the same..

Re: Rythmic Beat For Doctor Diesel

Posted: 25 Apr 2010
by Philhod
:lol: Beat me to it Doc. Yeah a locked up tappet would do that too, but if you haven't changed anything it probably is an injector. I have some spares if you want one.

Re: Rythmic Beat For Doctor Diesel

Posted: 25 Apr 2010
by jayw
Interesting thread...

When i got the Zant it billowed unburnt derv when started from cold which cleared in about 10 seconds. Replaced a leaking injector and it cleared. But, now it's back!

So, same issue i'm guessing?

Re: Rythmic Beat For Doctor Diesel

Posted: 25 Apr 2010
by Philhod
At the bottom of all injectors there are 1, 2, sometimes 3 washers. One of these is a copper fire washer. After removing the injector, if you don't replace that one with a new one each time, the injector seems to need cleaning regularly. If you do, they don't :)

That's all

Re: Rythmic Beat For Doctor Diesel

Posted: 03 May 2010
by Bx Bandit
It's stopped doing it now. I drained the tank from the Xantia and put in the BX (fuel smelt like mouldy damps rags) so as it's cleared I'm guessing it was due to the poor fuel.

Moving on to Jay's situation, it's reminded me of something that's been on my mind!

The pump I had from Vanny (a 1.9 TD Bosch) was a late but pre-ECU type pump. It had no timing advance device for cold starting. Normally, AFAIK, the timing advance was only fitted to the turbo models, which, certainly on the BX had the 'almost half' inlet valve opening time compared to the n/a's - so an advance mechanism makes sense.............BUT, recently on ebay there was a camshaft for a 1.9D/1.9TD Xantia. This must be wrong I thought, but at some point recently on pr-net a quick (but not throurough) check revealed the same camshaft for the n/a and TD! Did they fit an n/a to the TDs in the end or what???

Re: Rythmic Beat For Doctor Diesel

Posted: 03 May 2010
by docchevron132
AFAIK all 19D's and TD's had the same cam.
It was only the 17 that had different cas for N/A or Turbo

Re: Rythmic Beat For Doctor Diesel

Posted: 03 May 2010
by Philhod
The same part number was listed at Rigbye's for 19 n/a and 19TD when I checked. Just before I got the head off you Doc. 8)

Re: Rythmic Beat For Doctor Diesel

Posted: 04 May 2010
by Bx Bandit
So if they (Citroen, as in during production) used a different cammy in the 1.7 turbo, what made them change to using the same cammy betwixt the 1.9 n/a and TDs? Is it the same cam as used in the BX 1.9 n/a?

Re: Rythmic Beat For Doctor Diesel

Posted: 04 May 2010
by Philhod
Yes. But like Doc said, only in the 19 td

Re: Rythmic Beat For Doctor Diesel

Posted: 04 May 2010
by Bx Bandit
/\ But it could be a turbo spec cam used in the n/a! And more to the point why was the 1.7TD cam different, esp short inlet duration?

Re: Rythmic Beat For Doctor Diesel

Posted: 04 May 2010
by Philhod
[chin] They're not short duration as such, well they are but it's more a swifter open and shut via a peakier profile. Thus giving you much umph at the higher rev end and err... fuck all at the btm. That's why the 19n/a cam does work better. Because it has more bhp it is more pointy than the 17n/a, thus giving more btm sqirt and a little less top, but not as pointy as the 17 td.
Seeing as the 19n/a was appreciably earlier than the 19td, the n/a cam is probably the original and given the experience with the 17td, decided that the n/a cam was the best compromise. :wink: