I bought my 2004 1.8 TDCI LX (115k miles) for £1750 in May of this year & all seemed well, took a little starting in the morning but this being my first diesel didn't think anything of it. On giving it a full service soon after purchase I noticed one of the glow plugs was snapped so I was unable to replace. Over the following months as I investigated the removal of the damaged plug the car got harder & harder to start in the morning & once it did start a large amount of light coloured smoke followed for a few seconds but then cleared & the car ran fine. Eventually I removed the damaged plug in situ & thought all was well when I went for a run but then after 10 mins or so of seemingly fine running the car started to splutter & kick out darker smoke. I arranged for the car to be looked at by a professional & I was told all of the injectors needed replacing. I was unable to justify this cost (quoted £700+) so decided to opt for some used (not refurbished) injectors (£150) that had come from a running vehicle (or so I'm told). Once fitted the car is once again usable but still has it's problems. The starting remains the same, struggles to start then kicks out light smoke but then ticks over fine. On hard acceleration all seems well (perhaps a little dark smoke) but on slow acceleration or feathering the car coughs & splutters quite a lot. The car has had a full service (excluding cam belt) & I am now struggling to identify the problem. The mechanic that replaced & coded the injectors for me still thinks the problem lays with the injectors but I am not convinced & am looking for any opinions & advice that you guys may have to offer.

Thanks!

Firstly did you actually replace the glow plugs ? If so, the injectors may well be at fault. You can have them tested at most decent garages. Was the fuel filter changed, as this 'often overlooked' part of the service can play all kinds of tricks if its clogged up. A lot of the time this part is ignored in a service because unless you know what your doing, the system can be a bit of a pain to bleed up after fitting. The light smoke on first start up says glow plugs to me, mine use to be a little difficult to start as the cold weather crept in, also putting out smoke then clearing up. New plugs resolved both these issues for me.

glow plugs replaced, fuel filter replaced too. when I replaced all the glow plugs the car hasnlt started any different with the light smoke coming out for the first few seconds. I'm wondering know whether there could in fact be an electrical issue with the wiring for the glow plugs. Presumably I could do some kind of test with a voltmeter to ensure power is reaching all 4?

Yes you can test this, can't remember how I did mine, but did read alot about 'glow plug relay' being a possible cause also the wiring loom that runs from that to the underside of the fusebox, there were quite a few things it could have been, thankfully on mine, glowplugs cured it. Have a scout round on the internet for info, I had pages marked all over the place, just so I could get to it if needed.

not sure if it's relevant but I often get a smell of diesel waft through the car too?

Possible leaking injector seal ?

When you replaced the fuel filter you havnt dislodged the small o ring in the fuel pipe conector to the top of the filter housing had this problem with similar symptons on a mondeo can be a bit fiddly to get the o ring bacl in situ but if it is dislodged will allow air into system and starting problems and rough running also you should notice a slight diesel leak from where it connects to the filter housing i you do i would say this is your problem worth a look.

when you had the injectors replaced, were they coded to the ecu?

[quote name='James_Morpeth' timestamp='1356269454' post='222627']
glow plugs replaced, fuel filter replaced too. when I replaced all the glow plugs the car hasnlt started any different with the light smoke coming out for the first few seconds. I'm wondering know whether there could in fact be an electrical issue with the wiring for the glow plugs. Presumably I could do some kind of test with a voltmeter to ensure power is reaching all 4?
[/quote]

yes you could set your multimeter to 20v DC, connect one lead to earth and the other end to one of the glow plugs and turn the ignition on... you should now have battery voltage showing on your meter.