2.2 HDi Diagbox advice re injectors

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jml
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My Cars: A brilliant C8 2.2 HDi 173
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2.2 HDi Diagbox advice re injectors

Post by jml »

Help please ! Although I have a Diagbox, I really don’t know how to use it properly !

The fuel consumption of my car (C8 2.2HDi 173 hp)has deteriorated recently and it seems to smoke excessively on start up and for a little while afterwards. Additionally, as mentioned in another thread, it does smoke under hard acceleration. I wonder whether the injectors are getting dirty ?

I have run a Diagbox global test which showed the following. On a previous screen the system stated ‘ Correction of the injected flow of cylinder one by the engine management ECU the correction is active up to 3000 rpm and should not exceed +5 to -5 mg/stroke’

This being the case is the variation between cylinders in ‘Injector flow correction’ something I should be concerned about and does it suggest dirty injectors ?

Alternatively, is there something completely different I should be looking at ? Any help will be much appreciated :)
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Julian Leyton (RIP) 2023
vincentfishing
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Re: 2.2 HDi Diagbox advice re injectors

Post by vincentfishing »

I would look at build up of crud in egr and inlet manifold as source of your problems before injectors, Ive taken off egrs and inlet manifolds on a couple of diesels ive owned and the build up was ridiculous taking a couple of days of soaking with oven cleaner and repeat cleaning... I would try an aerasol can of egr cleaner sprayed into air inlet as a first resort as its the easiest first step in seeing if the black smoke reduces,
If your diy is up to it I would do an injector leak off test(plenty about how to do on web) which will show what condition they are in (how worn) and what they are like compared to each other,,,, but,,,,, wouldnt worry too much about them as first sign of worn injectors is longer turnover to start car which dramatically gets worse in cold winter weather ,eventually requiring easystart to get car to start,,
jml
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Posts: 258
Joined: 31 Jan 2013, 22:05
Location: Somerset
My Cars: A brilliant C8 2.2 HDi 173
x 37

Re: 2.2 HDi Diagbox advice re injectors

Post by jml »

Thanks for that (Vincent ?) all good suggestions and sorry for the late reply.

I don’t believe that the 2.2 173 has the swirl flaps that are prone to clogging up but cleaning up inlet and egr does all make sense. Throughout almost all of my car’s 170,000 miles I have used premium diesel which I hope has helped to keep things relatively clean and, up until now, I have not had any engine problems but a clean up could well be due.

Cheers

Julian
Julian Leyton (RIP) 2023
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