Injector testing and replacement

[Captain Jack]

Hello,

I obtained a spare injector for a princely sum of £16 from the HDI 90 - I assume it's the same as the one on 110. Tomorrow, I will try and do a leak-off test on my injectors on my 110 HDI to see if they are all working OK. So, the first question is how do I do it? Do I remove the clip holding the plastic T splitter thing on top of each injector and attach the tubes to whatever is under that?

Second, assuming I find that some of the injectors appear faulty and that I am able to remove them from the head, do I need any new seals? I seem to recall HBOL says I need to renew them but not sure which. Also, do I need to take any precautions when taking off the high-pressure metal pipes going to the injectors? I don't want to chop my fingers off (or worse). Do I need to leave the car standing for a little while or.....?

Cheers!
CJ

[Doggy]

Alex, have a look at my lash-up here: viewtopic.php?f=1&t=14490&hilit=wobble&start=15
You need some 3mm bore (I think it was), winscreeen washer hose and any identical bottles.

The seals you need are the copper ones you can see on the end of these injectors


There's no real worry about pressure, so long as you don't undo anything while it's running or cranking. The pressure decays very quickly when you stop the engine and the volume of the common rail is tiny anyway. I 'cracked' the unions and waited a second or two before undoing them fully, but I don't think it's an issue.

[Captain Jack]

Thanks Eric. I did actually read that thread several times but don't see exactly where the tube would plug into. I'll have a nab at the aux belt tomorrow and have a look at what's what. The actual testing will have to wait till later though as I don't have the bottles or, crucially, the tube. And it's Easter holidays....

Would seals be dealer only parts?

[Doggy]

I think you can get them from any diesel specialist, they'll probably be the same for any Bosch common rail injector.

You dont pull the tee-pieces out of the injectors, BTW, just pull off the interconnecting hoses. You have to blank off the unused ends of the tees and most importantly the return line, or it ends up messy.

Thius clip shows most of it http://www.youtube.com/watch?v=XPVZ6CkgKnw

[Welly]

I'd be surprised if the injectors are the same between the 90 and 110?

Swervicepox might confirm all this though?

[Captain Jack]

Thanks Doggy.

Welly, why would they be different? It's the same engine block, isn't it?

[Captain Jack]

I disconnected one of the injectors today and started the car. What I got is an engine running like a bag of spanners and the "wobble"! And an immediate aunty pollution message. So I guess all of the injectors are working - to an extent at least. Need to do the leak off lest.

[Doggy]

Adriano, (OdinEidolon), had a faulty injector in his 2.2, that was still OK electrically, but still wasn't injecting correctly. When he disconnected it, he got the customary A/P fault, but no change in the engine, so it might be worth trying all 4 in turn, if you can do it when it's misbehaving.

Best do the leak off test anyway, it's really easy, (even I managed it).

[GingerMagic]

Hi, I recently bought a mint '03 plate 110 for a couple of hundred quid, to use as parts for my 2.2. I only wanted the wing and tps but as it turns out the list is now on 21 items...!!

My dilemma is, it starts fine, everything electrical is working and only need front discs for MOT, but when engine is running it sounds like a skeleton masturbating in a filing cabinet...!! Something is very wrong with it, and the knocking is louder than a jackhammer.

I think it may be on 3 cylinders so will also try to test the injectors, can I just unplug the electric to each one in turn to see if engine changes characteristics?

Saw the leak off test on youtube but don't really understand the result...

If I can get this solved then I can use the car to replace my wife's 306. If not then there is soo many thing to take off and ebay.....

[Captain Jack]

Welp, my injector case comes to an end I think. Done the leak-off test today (after spraying half the engine bay with diesel) but all cups filled up to the same amount really. So, unless all injectors are broken, I think it's safe to say that they are all working OK.

That bloody rattle is getting on my nerves now though.

@GingerMagic

It does sound like one of your injectors isn't squirting diesel in. You can test it by unplugging each injector's wire in turn (turn engine off during plugging/unplugging) and see when there's no difference in engine note with a particular one unplugged.

The leak off test tells your how much diesel is returned from the injector (unused fuel) and if you get more unused fuel in one injector than from others (more than around 10% difference), you can assume that that particular injector isn't injecting enough fuel and is blocked/knackered.

[GingerMagic]

Thanks CJ, nice to have it in laymans terms.

I will test it later this week, will take a back seat as starter motor just failed on my 2.2 so may rob the 110 if its the same??

Will probably strip the 110 anyway, would be nice to find the fault just so I know what it is......