Refitting diesel injector

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hi1

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Back to the old citroen c1 problems.
Had to pull a diesel injector and have various asks
1 the hole it came out of has a carbon build up in it, anything to get the carbon off, done some scraping but would like a chemical if possible to make it squeaky clean. Looked at domestic oven cleaner but they all say don't use on ally. Don't want to buy 25 litres as for a wash any suggestions
2 the injector had a plastic skirt firmly stuck to it, how that's supposed to keep compression pressure back I don't know, however when refitting do you put the skirt in the hole and pass the injector through it or fit the skirt to the injector, if so how high up do you place it
3 the injector is held in place with a forked contraption which a bolt holds to the head. The torque loading shown in the citroen book states 2,5 which I believe is 2,5 newton meters? whatever they may be, this equates to 2lbft of torque, to hold an injector down against engine compression, does this sound right?
 
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Bear in mind that any crap that you dislodge will find its way into the cylinder, and any chemical such as oven cleaner is a complete no-no. I can't suggest any way of doing the clean up with the head on, sorry - unless you can find some method of plugging the injector hole and then blowing out any scraped debris with compressed air.
On the Isuzu diesel the skirt is placed in the hole first - maybe yours is similar?
You must use a new flame washer seal at the bottom of the injector before you pop it in, and the last time I torqued the securing fork up it was to 22 ft/lb. That was on an 8mm thread.
Sorry for not being much definite help here at all :(
John :)
 
Thanks for that
Put a bit of rag down the hole and vacuumed out any bits
Used to have a liquid when I was in the army for getting carbon off the high energy 'spark' plugs for the gas turbine engines. smelt foul but got the crud off. I did have a bit that I kept for 'research' but that ran out long ago.
I popped the skirt in there seems to be a bit of a recess for it to go and theres no indication how far up the injector to push it otherwise.
I put a new flame washer in. Interestingly enough the new ones supplied by an ebay stockist who went to the trouble of asking what car they were for are 2.5mm thick the ones supplied by the local citroen dealer , second time of being out, were at least a mm thinner, strange that its managed to blow by again.
I torqued the bolt to two white knuckles had one shear off last time wasn't fun to get the remains out.
regards
 
How does the engine run now? I presume your problem was blow by, causing carbon to form around the injector.....I hope you have it sorted - personally I've had one hell of a problem with some of these, Fords in particular.
This never happened when the injectors were screwed in!
John :)
 
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Halfway there. With the c1 you have to take all the intake plenum and associated pipery and ducting to get at the injectors so its time consuming. Hoping it was blow back, horrible smell of diesel but no apparent leaks from any of the pipes h.p or l.p and there was carbon on the skirt between skirt and wall of head so something has been squeezing past. Cant understand why they ever moved from threaded injectors, could be stiff to get out but at least they kept what should be kept inside the engine, progress I suppose.
 
Yes that's completely typical......often enough, the injectors stick in and have to be removed with a slide hammer :eek:
I've had two occasions on a Ford tdci 1.4 with leaking injectors, to the extent that fuel was running down the back of the engine - and I couldn't cure either. I reckon with those the answer was to have the injector lands spot faced on a milling machine which was somewhat out of my brief.
Maybe the clamp down injector method is just to allow accurate alignment of the HP pipes and electronics - I really don't know.
Anyway, please lets know how things go when its back together!
John :)
 
Maybe, Dave......for sure it could use the injector hole as a guide but any swarf would have to be got rid of.
There are a few specialist mobile firms which offer to remove any stuck injectors or indeed, machine the old one out if it won't budge.
Fairly intense engineering at the end of the day.
John :)
 
I've never liked the idea of doing any machining on a cylinder head while fitted. Seems wrong.
 
Too right - any swarf in there at all is asking for disaster one way or another.
I've witnessed stuck injectors being pulled out by a pneumatic slide hammer......unbelievable violence :eek:
John :)
 
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