Xantia 1.9TD reluctant to start when hot

[Old-Guy]

Spooky or what?

Bearing in mind that Saturday was All Hallows (All Saints) Day:

Running about on various household errands on Saturday gave me the opportunity to 'test' my hot starting problem.

To begin with it wasn't as bad as is had been when I first posted this topic. On my one test of continuous cranking, it started relatively quickly - though nothing like as quickly as I would like.

I pulled out the tank unit. Not at all difficult - one jubilee tried to hide by sliding down its pipe, so I tightened a long cable tie on each pipe to stop the clips from disappearing and give me something to hold onto the pipe with. I've left them in place for next time.
Anyway, tank filter clean as a whistle. Put it back carefully and did up the jubilee clips - tight but not too tight.
Did a supermarket run (8 miles each way), re-started instantly less than half-an-hour later. Picked my wife up from work later on - again started instantly, this time after a 10-15 minute wait. Dropped her at the front door - instant restart to put the car away. When I say instantly, I mean 2nd or 3rd cylinder on compression - what I expect.
I've made the problem go away, rather than fixed it (knowing what I did to effect a cure). I'm always uneasy when this happens with a PC.

I can only think of 2 things:
1. Being very aware of what I'm doing, I've been watching for the glow light to go out before I turn the key rather than switching on, keying the security code and cranking.
2. Could there have been a very slight air leak from where the supply pipe goes onto the tank unit which I fixed by doing the clip up a bit tighter?

[CitroJim]

Guy, that's interesting

I know exactly what you mean about fixing it without really determining the real fault

Two thoughts come to mind, IDI diesels, especially Turbos, need all the pre-heating they can get, even when hot. Firstly because combustion is initiated in a pre-chamber, and secondly because the compression ratio is below optimum for an NA diesel, which it is effectively with no turbo spinning. So even when hot, full glowplugs are always needed. Bizarre I know but that's IDI Turbos for you.

An NA XUD engine, having a much higher compression ratio, often needs no pre-heating for a hot start. The same, for reasons I've never satisfactorily explaind to myself, applies to the 2.1TD The 1.9TD though, does have a paricularaly low compression ratio for a diesel.

Secondly, a tiny air leak anywhere on the fuel lines, feed or return, will cause a run-back of fuel to the tank so a tiny air leak at the tank-end jubilee clip could wee have been the root cause.

I trust it'll continue to be have itself now!

[Old-Guy]

Me too!

Thanks for all the suggestions chaps.

Guy